 -- THIS IS A RUSH TRANSCRIPT FOR 'THIS WEEK' on April 9, 2017 and it will be updated.

(BEGIN VIDEOTAPE)

ANNOUNCER: Starting right now on THIS WEEK with George Stephanopoulos, strike on Syria.

After that horrific chemical attack --

DONALD TRUMP, PRESIDENT OF THE UNITED STATS: No child of God should ever suffer such horror.

ANNOUNCER: -- the commander in chief's rapid response. But by targeting the Syrian regime, is the U.S. now in a collision course with Russia?

REX TILLERSON, SECRETARY OF STATE: It's very important that the Russian government consider carefully their continued support for the Assad regime.

ANNOUNCER: Secretary of State Rex Tillerson is here in his first Sunday interview.

And, after promising to focus here at home --

TRUMP: I don't want to be the president of the world. I'm the President of the United States.

ANNOUNCER: -- is the America First president going global?

TRUMP: I now have responsibility and carry it very proudly.

ANNOUNCER: Two key players in Congress weigh in: Senator Marco Rubio and Congressman Adam Schiff. A pivotal week as the Trump presidency opens a new chapter.

From ABC News, it's THIS WEEK. Here now, chief anchor George Stephanopoulos.

(END VIDEOTAPE)

GEORGE STEPHANOPOULOS, ABC HOST: Good morning. All through last year's campaign, Candidate Trump promised to stay out of Syria. Not our fight, he said. It's time to put America first. This week, that all changed. The spark? These images. Syrian children suffocating, gassed by the Assad regime.

An with that, the man who pounded President Obama for his red line in Syria reversed course in the Rose Garden, drawing lines of his own.

(BEGIN VIDEO CLIP)

TRUMP: When you kill innocent children, innocent babies -- babies, little babies -- with a chemical gas that is so lethal, that crosses many, many lines. Beyond a red line.

(END VIDEO CLIP)

STEPHANOPOULOS: The big difference? After prolonged deliberation, President Obama refused the retaliate. President Trump's response was lightning fast, a targeted cruise missile strike plus an expansive call to arms.

(END VIDEO CLIP)

TRUMP: Tonight, I call on all civilized nations to join us in seeking to end the slaughter and bloodshed in Syria.

(END VIDEO CLIP)

TRUMP: The question now is how? This morning, Assad is defiant. His airfield hit by those tomahawks is up and running. The region he gassed on Tuesday is getting bombed again.

So what will President Trump do now? Will Thursday's strike be followed by a new strategy to remove Assad from power? That was my first question for Secretary of State Rex Tillerson in his first interview on THIS WEEK.

(BEGIN VIDEOTAPE)

TILLERSON: Well, George, I think our strategy in Syria, as you know, our priority is first the defeat of ISIS, remove them from access to the Caliphate because that's where the threat to the homeland and to so many other homelands of our coalition partners is emanating from. Once we can eliminate the battle against ISIS, conclude that and it is going quite well, then we hope to turn our attention to cease fire agreements between the regime and opposition forces. And in that regard, we are hopeful that we can work with Russia and use their influence to achieve areas of stabilization throughout Syria and create the conditions for a political process through Geneva in which we can engage all of the parties on a way forward.

And it is through that political process that we believe the Syrian people will awfully be able to decide the fate of Bashar al-Assad.

STEPHANOPOULOS: But is that political process -- is that diplomatic process now going to require greater military force to increase your leverage. You've seen Senators McCain and Graham call for taking out the Syrian air force, call for creating safe zones in Syria.

TILLERSON: Well, as you know, George, the situation in Syria relative to the battlefield is quite complex because there are multiple engagements under way. As I said, we have the war to defeat ISIS in which many of those battle plans are being coordinated between the US, its coalition agreements, Turkey, some of the Syrian opposition and others and it is being coordinated somewhat with the Syrian regime and the Russian forces to put pressure on ISIS to eliminate them.

Having said that, there are other battle areas still underway between the opposition and regime forces and it's further complicated that we have the presence of a number of al Qaeda forces inside of Syria, so the country is in a very chaotic situation relative to the battlefield.

But having said that, that just demands greater effort on the part of a large array of coalition parties, both regionally, as well as those are directly engaged in the fight itself inside of Syria. So I'm not suggesting this is going to be a simple way forward, but we do have, I think, a fairly good consensus building among a number of those parties who would be part of the process that this is the -- this is the best way forward.

STEPHANOPOULOS: Russia doesn't seem to be part of that consensus. President Putin has called what happened on Thursday a significant blow to the relationship with the United States.

TILLERSON: Well, I guess I'm not too surprised that Russia might make that statement. I will tell you, I'm disappointed, because I think the real failure here has been Russia's failure to live up to its commitments under the chemical weapons agreements that were entered into in 2013, both by the Syrian government and by Russia, as the guarantor, to play the role in Syria of securing chemical weapons, destroying the chemical weapons and continuing to monitor that situation.

And so the failure related to the recent strike and the recent terrible chemical weapons attack, in large measure, was a failure on Russia's part to achieve its commitment to the international community.

STEPHANOPOULOS: I want to get into to Russia a little bit more in a second.

But a couple more questions first directly on Syria.

You mentioned, again, that the outcome of the political process will be that the Syrian people can decide the fate of Assad.

When you said that first last week, on March 30th, in a meeting with the Turkish president, are you worried at all that that was taken as a green light by Assad to launch that chemical attack?

TILLERSON: George, I don't -- I don't see how that could be the case. You know, this is not the first chemical attack launched by Assad. In fact, there were two other chemical attacks the week of March 25th and the 30th. And there have been chemical weapons attacks made by the Bashar al-Assad regime in the past. So this was just the latest of a series of violations.

STEPHANOPOULOS: But you accept that right now, the Syrian people have no way to remove Assad. That's going to take greater pressure, from the United States, from an international coalition, perhaps military pressure.

TILLERSON: Well, ultimately, it could, George. But, you know, we've seen what that looks like when you undertake a violent regime change in Libya. And the situation in Libya continues to be very chaotic. And I would argue that the life of the Libyan people is not all that well off today.

So I think we have to learn the lessons of the past and learn the lessons of what went wrong in Libya when you choose that pathway of regime change.

So we know this is going to be hard work, but we think it's also a process that will lead to a durable and lasting stability inside of Syria. Any time you go in and have a violent change at the top, it is very difficult to create the conditions for stability longer-term.

STEPHANOPOULOS: So it sounds like from what you're saying right now, there is no real change in the United States' military stance towards Syria from what it was last week.

TILLERSON: That's correct, George. This strike -- and I think the president was very clear in his message to the American people that this strike was related solely to the most recent horrific use of chemical weapons against women, children, and, as the president said, even small babies. And so the strike was a message to Bashar al-Assad that your multiple violations of your agreements at the U.N., your agreements under the Chemical Weapons Charter back in 2013, that those would not go without a response in the future.

And we are asking Russia to fulfill its commitment and we're asking and calling on Bashar al-Assad to cease the use of these weapons. Other than that, there is no change to our military posture.

STEPHANOPOULOS: You mentioned earlier -- you mentioned Russian complicity, perhaps, with the chemical program in Syria. We now know, according to U.S. military officials, there were anywhere from 12 to 100 Russians on that base when the chemical attack was launched.

Does that suggest to you that the Russians knew or should have known what was going on, that they were complicit?

TILLERSON: Well, George, I've not seen any hard evidence that connects the Russians directly to the planning or execution of this particular chemical weapons attack. And, indeed, that's why we've tried to be very clear that the Russians were never targeted in this strike. This strike was to target the air base from which these chemical weapons attacks were launched and to take -- to render that air base, and certainly its infrastructure, no longer usable.

So I think the strike -- it was well planned, it was proportional, it was directly related to the chemical weapons attack and no other parties were targeted.

STEPHANOPOULOS: At a minimum, Russia hasn't done enough to get rid of that chemical stockpile, because it's still there and the Russians are still on that base.

One of our next guests, Congressman Adam Schiff, has said you should deliver an ultimatum to Foreign Minister Lavrov when you meet with him next week on this issue.

Will you do that?

TILLERSON: Well, we've already, I think, issued some very strong statements, George. And, yes, that will part of the discussions when I visit Moscow next week, is to call upon Foreign Minister Lavrov and the Russian government to fulfill the obligation it made to the international community when it agreed to be the guarantor of the elimination of the chemical weapons. And why Russia has not been able to achieve that is unclear to me. I don't draw conclusions of complicity at all. But clearly, they've been incompetent, and perhaps they've just simply been out-maneuvered by the Syrians.

STEPHANOPOULOS: Do you think is an opportunity, are you hoping this is an opportunity perhaps to drive a wedge between Assad and Putin, to drive Putin into a -- into a commitment right now to do more to remove Assad?

TILLERSON: Well, George, I'm hopeful that we can have constructive talks with the Russian government, with Foreign Minister Lavrov and have Russia be supportive of a process that will lead to a stable Syria.

Clearly, they are Bashar al-Assad's current ally. They should have the greatest influence on Bashar al-Assad, and certainly his decisions to use chemical weapons, they should have the greatest influence on him to cause him to no longer use those.

I hope that Russia is thinking carefully about its continued alliance with Bashar al-Assad, because every time one of these horrific attacks occurs, it draws Russia closer in to some level of responsibility.

STEPHANOPOULOS: And if we determine they are responsible, what will happen?

TILLERSON: Well, that is going to be clearly very damaging to U.S.-Russian relations. I do not believe that the Russians want to have worsening relationships with the U.S., but it's going take a lot of discussion and a lot of dialogue to better understand what is the relationship that Russia wishes to have with the U.S.

STEPHANOPOULOS: Well, one of the big issues complicating that relationship, of course, is Russian interference in last year's election. That's the consensus view of all of our intelligence agencies.

Is that on the agenda for your meeting with Foreign Minister Lavrov? And what can you say to them? What will be the consequences if Russia tries something like that again?

TILLERSON: Well, George, we have had previous conversations about it when I met with Foreign Minister Lavrov in Bonn, Germany on the margins of the G20. We will continue to talk with them about how this undermines any hope of improving relations, not just with the United States, but it's pretty evident that they're taking similar tactics into electoral processes throughout Europe.

And so they're really undermining any hope for improved relations with many European countries as well. So, this is something that Russia needs to confront themselves. And I think examine carefully as to how is this helping them achieve their longer term objectives.

STEPHANOPOULOS: And U.S. sanctions will remain in place?

TILLERSON: There is no reason to be lifting sanctions, George. The reason the sanctions were put in place continue to exist. There's been no change of the status of the situation in Ukraine or Crimea. And those sanctions will remain in place until those issues are addressed.

STEPHANOPOULOS: What message do you think North Korea should take from President Trump's decision to strike Syria last week?

TILLERSON: Well, I think the message that any nation can take is if you violate international norms, if you violate international agreements, if you fail to live up to commitments, if you become a threat to others, at some point a response is likely to be undertaken. And I think in terms of North Korea, we have been very clear that our objective is a denuclearized Korean peninsula. We have no objective to change the regime in North Korea, that is not our objective. And so the whole reasons underlying the development of a nuclear program in North Korea are simply not credible.

STEPHANOPOULOS: There's been at least one report that the United States has drawn up plans perhaps to consider assassinating Kim Jong-un. That's not true?

TILLERSON: I am aware of no such plans.

STEPHANOPOULOS: In the president's meeting with President Xi of China, you know, the president has often complained that China isn't doing enough to take on the North Korean nuclear program. Did he convince President Xi to stake more aggressive action? And what was the response of the Chinese to the president's determination to go it alone if he must?

TILLERSON: George, I can tell you that President Trump, President Xi had very extensive discussions regarding the serious situation in North Korea. They met for quite some time, one on one, to discuss North Korea. And there was a full range of options that were discussed between the two leaders.

President Xi expressed agreement that the situation has reached a new level of seriousness and threat. He expressed a view that he wanted to be supportive in terms of causing the regime in Pyongyang to change its view around the future need for those weapons. China has expressed on multiple occasions, and they reaffirmed it in our discussions with us here in Mar-a-Lago that their policy is unchanged and that is for a denulclearized Korean peninsula.

STEPHANOPOULOS: But are you seeing the actions you need to see?

TILLERSON: Well, we'll wait and see, George. It's only be a couple of weeks since we announced our policy changes and have called on the government on China to take additional steps. We expect that they will. They have indicated that they will. And I think we need to allow them time to take actions, and we will continue to be in very close discussions with them.

The conversations have been very open, George, and very candid.

STEPHANOPOULOS: How much time do we have with North Korea? How close is Kim Jong-un to developing a weapon that could actually reach the United States?

TILLERSON: Well, the assessments are, obviously, somewhat difficult. But clearly, he has made significant advancements in delivery systems. And that is what concerns us the most.

The sophistication around their rocket launch programs, their sophistication around the type of fueling that they use, and they're working their way towards the test of an intercontinental ballistic missile.

And these are the kinds of progress that give us the greatest concerns. So we have been quite clear with the regime in Pyongyang that that's what we want them to cease.

So what we would hope is that with no further testing, obviously their program doesn't progress. And that's what we have asked for, is for them to cease all this testing before we can begin to think about having further talks with them.

STEPHANOPOULOS: And that development of an intercontinental missile, that's a red line for President Trump, isn't it?

TILLERSON: If we judge that they have perfected that type of a delivery system, then that becomes a very serious stage of their further development.

STEPHANOPOULOS: Finally, sir, on the issue of Mexico, you met with the Mexican foreign minister at the State Department this week. In that meeting, did you make it clear that the United States expects Mexico to pay for the border wall President Trump has proposed?

TILLERSON: No, we had no conversation about that issue, George. We were -- we have had, I think, very productive talks around actions that can be taken to slow and stem and discourage transmigration of people coming from Central America through Mexico and entering the United States.

And, in fact, I know you have -- I'm sure you have seen the data that is coming out and the level of immigration -- illegal crossings from Mexico, whether it's Mexican nationals, but in particular of Central American nationals, has dropped dramatically.

So I think Mexico is quite pleased. And we have had a number of discussions with them on how we work together to continue to make further progress.

STEPHANOPOULOS: That's surprising to me, no discussion of paying for the border wall, since President Trump spoke about it so often during the campaign. Is it the policy of the United States that Mexico must pay for that wall?

TILLERSON: George, it's just not part of our discussions between the foreign minister and myself. We're also talking about how to organize even a greater effort around transnational crime and counternarcotics, to stem the flow of narcotics that flow into the United States, and the flow of weapons from the United States into Mexico that supports the cartels.

So we're really focused on working at very high levels to address some of these problems and challenges that are really in the interest of both of our countries to make progress on.

STEPHANOPOULOS: Mr. Secretary, thanks for your time this morning.

TILLERSON: It's my pleasure, George.

(END VIDEOTAPE)

STEPHANOPOULOS: Let's get some analysis now from Tom Friedman, the Pulitzer Prize-winning foreign policy columnist from The New York Times.

Tom, thanks for joining us this morning. You just heard Secretary of State Tillerson there, no change in the United States military strategy towards Syria. I guess the big question is, what is the strategy right now?

TOM FRIEDMAN, "THE NEW YORK TIMES": Well, what I heard, George, are basically three messages. One is that the Trump people feel that in launching this cruise missile attack in retaliation for Assad's use of chemical weapons that they have reduced the chances that Assad will use such chemical weapons again or that somebody else will. That's not an unimportant thing.

I think they also feel they have increased the uncertainty in places like North Korea as to whether the U.S. will use force if the North Koreans cross that red line on intercontinental ballistic missiles.

But what I think he also made clear was that right now this administration is not interested in going any further than the Obama team did in terms of actually changing the balance of power on the ground between the opposition forces, the pro-American opposition forces there, the Assad regime, and the Russians and the Iranians who are backing them.

And without that, it's hard to see any long-term change right now. But it's still early in the process.

STEPHANOPOULOS: Yes, and the question is, what kind of leverage you can use with Russia to get them to pull away from Assad. That doesn't appear to be happening right now.

I was struck by something King Abdullah said to Lally Weymouth of "The Washington Post" this morning. He suggested that the United States should consider concessions on Crimea to cleave Putin away from Assad. Good idea?

FRIEDMAN: I would really think twice about that. You know, I think these two theaters are very different. I mean, it would obviously depend on what Assad was -- what Putin was ready to do in Syria, whether he was really ready to break the alliance with the Iranians, and create a process by which you're easing Assad out of power and really partner with the world community in creating a different kind of political structure in Syria.

If he's ready to go that far, well, you could certainly think about it. But I'd be very careful about that.

STEPHANOPOULOS: How do you make sense of the president's pretty dramatic turnaround this week?

Your colleague in "The New York Times," Peter Baker, talked -- called it a highly improvisational, situational approach toward foreign policy. You know, just last week, we saw Secretary Tillerson talking about the Syrian people making a decision on Assad. We saw President Trump all through the campaign saying we can't get involved in this fight.

Real change this week.

FRIEDMAN: Well, look, George, in fairness, Syria is the problem from hell. And, you know, it's such a fragmented situation on the ground right now, you know, what I saw in Secretary Tillerson there talking about it is, you know, why didn't I raise my hand to be secretary of Agriculture, not secretary of State?

Because, it's really a difficult, difficult situation.

So the real question is, I think, is two things, George.

One is can we increase our leverage there without putting American troops on the ground, by maybe giving more aid to the opposition forces there, considering a no-fly zone?

I mean that's a big NATO-wide question.

You know, one thing I'm asking myself today is where are Trump's -- where is Trump's Twitter feed when we need it?

You know, if I were Trump right now, I'd be hammering Putin on the fact -- and the Iranians. You are a protector of someone using poison gas. Putin, you were either feckless and didn't know your ally was doing this, or you're complicit.

And I don't think these guys like to be, actually, called protectors of someone using poison gas.

So I would be doing everything I could on every front to increase our leverage, because in the Middle East, if you're trying to do diplomacy without leverage, you're playing baseball without a bat.

STEPHANOPOULOS: And we'll see if Secretary Tillerson brings that message to Lavrov this week in Moscow.

I wonder if you looked, also, at all the events of this week.

Steve Bannon off the National Security Council, McMaster asserting himself as the national security adviser. You have Secretary Tillerson in that interview right there, fairly tough talk on Russia, completely dismissed the idea of Mexico paying for the wall. General Mattis at the heart of these decisions on Syria.

Are we seeing these outsiders assert themselves?

FRIEDMAN: Yes, I think we're seeing a reversion to the mean. You're seeing a reversion to sort of closer to the natural interests of American foreign policy and to the limits of what the American people are really ready to do and tolerate right now.

You know, my friend, Michael Mandelbaum, said to me the other day that, you know, the biggest restraint on American intervention in Syria is democracy in America, the fact that there's just a lot of Americans -- and we see this in the Congress -- that are wary of getting involved.

So I think all of that crazy rhetoric from the campaign, you saw it on them paying for the wall in Mexico, that will gradually be muffled out and faded away from.

STEPHANOPOULOS: Tom Friedman, thanks for joining us this morning.

FRIEDMAN: Thanks, George.

STEPHANOPOULOS: More analysis from our roundtable coming up.

And up next, two leaders in Congress on what's next after this week's airstrikes signal for U.S. strategy in Syria and our tense relationship with Russia. Marco Rubio and Adam Schiff join us live.

(COMMERCIAL BREAK)

(BEGIN VIDEO CLIP)

SEN. MARCO RUBIO (R), FLORIDA: I have never supported the use of military force of U.S. military force in this conflict and I still don't. I believe that U.S. military action of the type contemplated here may prove to be counterproductive. After a few days of missile strikes, it will allow Assad, for example, to emerge and claim that he took on the United States and survived. And by the way, I also think this action could unleash a series of events that could further destabilize the region.

(END VIDEO CLIP)

STEPHANOPOULOS: Senator Marco Rubio back in 2013 warning against what he called pinprick military strikes against Bashar al-Assad in Syria. He's joining us now this morning. Senator Rubio, thank you for joining us this morning.

RUBIO: Thanks, George.

STEPHANOPOULOS: That was back in 2013. You praised President Trump's strike this week as a first step in a longer strategy. But are you worried based on what we're seeing from Assad this morning, the airfield up and running again, his defiance, that the consequences you feared back in 2013 are coming through now?

RUBIO: Well, first of all, the consequences actually happened. And I would say that three-and-a-half years is a long time.

Here's a loft things that have changed. Here's the first thing that's changed from 2013 to now, the Russians are now there. Assad was losing back in 2013. If we had armed non-jihadist elements on the ground, they could have overthrown him. That's what I thought was the better approach at the time.

The second is that the administration, what they were proposing, had no clear objective. They wanted to blow up some things to send a message. I don't think you use the U.S. military simply to send a message. This strike was limited, but it had a clear strategic objective, which was the destruction or degrading of a key airbase installation that is used in these chemical attacks.

That said, look, I listened to the interview earlier today, I guess, that Secretary Tillerson is going to have on your program, and I'm a bit concerned about the outlines of the strategy, as I understand it. I think it's based on assumptions that quite frankly are not the right ones. And I hope they'll reconsider this idea that we're going to get rid of ISIS and then we'll hopeful use Assad and others to come up with a solution, it's not going to work.

As long as Assad is there, you're going to have a radical jihadist Sunni element, even if you destroy ISIS it'll be al-Nusra and that new coalition. These people who have been killed and gassed and human rights violations against them will never accept Assad as their rightful ruler, and they will join or become radicalized in order the fight him.

STEPHANOPOULOS: So what should they be doing instead?

RUBIO: Well, here's the first thing I would tell you is, we have to -- and I agree with you, there has to be a strategy outlined that is based on reality. This is not Libya. I also heard that he kind of analogized it to Libya. The Libyan situation -- Libya, Gadhafi was overthrown by his people. What happened afterwards, the lack of a strategic plan or engagement by the international community after Gadhafi's removal is what's led to the chaos that we see in Libya today.

On the case of Syria today, it's much more complicated than it was three, four, five years ago. But there are still things that can be done. We should be increasing sanctions significantly on Iranian and Russian interests that are helping Assad, and particularly this Boeing deal should be canceled. The second thing we that we need to examine is how can we suppress the air defenses of the Assad regime? And that may include coalition use of force to ensure that these offensive operations from the air are not happening, and by the way keep our troops there. Beyond that --

STEPHANOPOULOS: But you can't do that if Russia's not on board, can you?

RUBIO: What's that, I'm sorry?

STEPHANOPOULOS: You can't do that if Russia is not on board, can you?

RUBIO: Well, listen, here's the bottom line. If those air strikes are being used not just to attack civilians and innocents on the ground, but also threatening the over 500 American servicemen and women who are on the ground in Syria, we have a national security interest in protecting them from air strikes. By the way, that was one of the factors I think should have been in play in this particular attack. The presence of sarin gas and its use in a country where there are Americans embedded alongside forces, working to defeat ISIS, is a clear and present danger to the men and women who serve us in uniform.

I also think we need to rebuild and reinvigorate the non-jihadist elements on the ground. It's going to be harder than it was three or four years ago, but I still think possible to identify elements on the ground that are not jihadists who we can help to become players both on the negotiating table and in southeastern and southern Syria, to be major players in the future of Syria as an alternative to Assad.

STEPHANOPOULOS: You know, when we talked on Friday, you suggest that you thought the administration was moving in the direction you're outlining right now. After listening to Secretary of State Tillerson this morning, do you still believe that?

RUBIO: Well, I'm concerned. And there seems to be a difference between what Ambassador Haley is saying, as she said last night, that Assad really has no future, and what I heard this morning from Secretary Tillerson.

But, look, I don't mean to pick a fight with anyone here. What I'm telling you is I think that the strategy he seems to be outlining is based on assumptions that aren't going to work. There is no such thing as Assad, yes, but ISIS, no. This focus that you can defeat ISIS as long as Assad is there is not true. They're two sides of the same coin.

As long as Bashar al-Assad is in power in Syria, you will have a reason for people to be radicalized in Syria. And that's what's going to happen. And, by the way, in all this about ISIS -- there's an al Qaeda group growing in strength, this al-Nusra coalition, that are prepared to step into the vacuum left behind by a defeated ISIS. You cannot have a stable Syria without jihadist elements on the ground as long as Bashar al-Assad is in power. And the quicker they realize that, the better our strategy's going to be. But this idea that somehow you can just defeat ISIS and then we'll figure it out with Assad, it's not going to work.

STEPHANOPOULOUS: On the subject of Mexico, you heard Secretary Tillerson there say he didn't even bring it up, Mexico paying for the wall, when he met with Mexican Foreign Minister this week. It seems like that idea of Mexico paying for the wall is dying a slow death.

RUBIO: Well, we met with the foreign minister as well and it did come up in our meeting. And let me just say, Mexico's not going to pay for the wall. And, by the way, America should, if we believe that's in our national interests to do so.

But I do think there's a lot we can work on with Mexico. I think the Mexican government is open, for example, to renegotiating key points of NAFTA on intellectual property as an example. I think they have a real interest in their border security, in their southern border. I think Mexico's willing to be a partner in El Salvador, Guatemala, the Honduras, the Northern Triangle countries that are the source of a lot of the migration that's coming in through Mexico. Mexico's as much a transit point now as it is a source of origin for people coming into the United States.

I think there's a lot of military to military engagement with Mexico. There's a lot we can work on together. I left that meeting feeling pretty positive about what about we can do with our relationship. And I hope that's the direction it continues.

STEPHANOPOULOUS: Finally, you're also a member of the Senate Intelligence Committee. President Trump told "The New York Times" this week that he thinks that Susan Rice, President Obama's national security adviser, may have committed a crime. He offered no evidence for this at all, but may have committed a crime as she was reviewing those intelligence files that had dealt with the Trump transition.

As I said, you're a member of the Intelligence Committee. Have you seen any evidence at all to back up a claim like that?

RUBIO: Well, I usually try not to opine on those issues. Suffice it to say that I have not seen anything like it.

But let me say this, I thin we've learned over the last couple of weeks how bad it is to kind of be talking and debating these things in front of the media. If you're serious about a fact-finding mission, you wait until all the facts are in, you write a report, we make them public, and then you and members of the Senate and the House, the American public, can look at those facts and decide where we should go from there.

And that's what we're in the process of doing. And I'm very proud of the work of the intelligence community -- the Intelligence Committee is doing in the Senate. It's bipartisan. Everyone's working hard. No one's out there trying to turn this into a way to get famous.

And I think I'm more confident than ever that we're going to prepare a package, we're going to prepare a report that's going to lay out all the facts, across a number of topics, and that we'll allow you and others to look at it and from there draw conclusions about what should happen next and who was involved and who wasn't.

And I just ask everyone for a little bit of patience. It's not going to be as fast as you want, but it's going to be done right. And I'm more confident today than I've ever been about that.

STEPHANOPOULOS: Senator Rubio, thanks for joining us this morning.

RUBIO: Thanks, George.

STEPHANOPOULOS: And we are joined now by the top Democrat on the House Intelligence Committee, Congressman Adam Schiff.

Congressman, thank you for coming in this morning.

REP. ADAM SCHIFF (D-CA), HOUSE INTELLIGENCE COMMITTEE: You bet.

STEPHANOPOULOS: Let's pick up where we just left off with Senator Rubio right there. A lot of changes this week on your committee. The chairman, Devin Nunes, has stepped aside now from the Russia investigation. And I know you think that is appropriate.

He's now facing an Ethics Committee investigation about revealing intelligence while he was chairman.

Do you believe those claims are justified?

SCHIFF: I don't know, George. And I really don't want to opine on the ethics investigation.

I can say I think he made the right decision to step aside and let someone else lead from the GOP point of view. I think it does get our investigation back on track. It gets our Committee back on track and that's very positive.

I do think, also, we saw just the events of the last 48 hours, why it is so important on the broader issues that the president have a responsible, respectful relationship with the intelligence community. This is the first life or death decision this president has made on the basis of intelligence that was provided to him.

Now, he didn't, apparently, seek the support of our allies, but had he done that, he would have gone to them and said this is what our intelligence shows. This is why we think the Russians are lying. They need to be able to believe our intelligence, as the American people do. And I hope this underscored for the president why the destructive relationship he's had has to come to an end.

STEPHANOPOULOS: I want to pick up on Syria in a moment.

One more question on your investigation.

I don't know if you've seen this, but your former colleague in the House, Mike Rogers, also CIA director, has suggested that you should also recuse yourself now from the Intelligence Committee investigation.

Here's what he wrote. He said, "Representative Adam Schiff should consider recusing himself from the probe for his part -- Schiff's suggestion to the media that he had seen information on Russia-Trump campaign ties that was quote, "the kind of evidence that would be presented to a grand jury," adding that he had seen additional evidence but not elaborating further," suggesting that you also revealed intelligence you shouldn't have.

SCHIFF: You know, a lot of us have characterized how we've seen the intelligence. Some have said it looks more like smoke than fire. Some of us said it's a small fire. Some have said they've seen no evidence. Mr. Rogers and others don't quarrel with those who say they've seen no evidence.

I don't think that's an accurate assessment. And I certainly don't think I can let it stand.

But I don't think Mr. Rogers' suggestion is a serious one.

STEPHANOPOULOS: And is your investigation now back on track?

SCHIFF: It is back on track. We have exchanged witness lists. I think we're largely in agreement with those witness lists. We're also discussing moving forward in terms of our Committee hearings.

So, you know, I can happily report that I think we are back to where we were before the whole White House excursion. And I think that's enormously important for the investigation.

STEPHANOPOULOS: And I wonder what you make of Secretary Tillerson. I posed the question, you said he should deliver an ultimatum to the foreign minister of Russia when he meets with him Tuesday.

Is that what you heard this morning?

SCHIFF: Well, it does sound like it's what I heard, although I was suggesting that frankly, before the strike, not after it, but nonetheless, I think there is a strong moral case to have -- to make for what the president did, stronger now, in fact, than when President Obama faced that same situation, because when President Obama did -- and I think the use of military force always has to be the last response, not the first -- he was presented with a diplomatic alternative that the Russians put on the table.

And I think you exhaust all those diplomatic alternatives. That ultimately didn't work. The Russians didn't sufficiently enforce it. Assad violated that agreement. And I think that makes the moral justification the answer to that Syrian father's question, how can the world allow this to go on, that much stronger today than it was in 2013.

But I don't think, George, it should have been done without Congressional approval. I don't think, frankly, Obama should have put troops back in Iraq or in Syria without Congressional approval. I don't think this president should have taken that strike without Congressional approval.

I also think that...

STEPHANOPOULOS: Doesn't he have the inherent right, under "The Constitution," to do that?

SCHIFF: I don't think so. I don't think so. Now, you can call argue -- and President Obama did -- that if this is limited, if it's not for warfare, that he has the Article Two power to do that. I also think, frankly, that Congress has itself to blame here. We've sat on our hands for years. I've introduced an authorization of the use of force. I couldn't get a single vote on it. No one could.

And so we have weakened our own role in the checks and balances. I think Congress needs to step forward immediately.

STEPHANOPOULOS: But do you think Congress could even come close to agreeing on a use of force resolution at this point?

SCHIFF: You know, I do. And I always have, and I have for years. It's certainly not easy. And what I propose that we do -- because there are certain Republican red lines and Democratic red lines -- we're not going to allow a resolution that doesn't have a sunset. We have seen the problem with one that has gone on indefinitely now.

The Republicans don't want to see one that limits the president's hands geographically. I think we can come to agreement on a resolution that says the president will have the authority to go after al Qaeda and ISIS and the Taliban, but if he should use this authorization, it will trigger an opportunity for any member of congress to force a vote to either repeal the authorization or revise it in some way.

That kind of formula, I think, might make sense to both Democrats and Republicans, liberals and conservatives, because it forces accountability.

STEPHANOPOULOS: You also heard Secretary Tillerson issue some sort of warning to Russia about interfering in elections here again and also overseas as well. Quite a different from we've heard from President Trump in the past.

Is it going to be possible to reset our relationship with Russia as long as your investigations are still outstanding?

SCHIFF: I don't think our investigation is the obstacle to a different relationship with Russia. I think Russia is the obstacle. Their interests are not aligned with ours except in very narrow areas

Certainly, they're not aligned in their invasion of Ukraine and their possession of Crimea illegally. Their not aligned in Syria where their primary object, contrary to what the president has said, has not been going after ISIS, it's been going after the moderate opposition to the Assad regime.

They're not aligned with respect to NATO, which they want to see weakened. They're not aligned in Europe, which they'd like to see dissolved.

So, those are the impediments, not our investigation.

STEPHANOPOULOS: Was Russia complicit in the chemical weapons strike?

SCHIFF: Absolutely they're complicit. Russian intelligence may not be as good as ours, but it's good enough to know the Syrians had chemical weapons, were using chemical weapons. And indeed if the Russians had a presence on that airfield, and even if they didn't, they are smart enough to know exactly what is going on there.

They're better positioned to know in the sense that they have people on the ground in close proximity working in close concert with the regime. I think absolutely they know what the Syrians are doing.

STEPHANOPOULOS: Congressman Schiff, thanks for your time this morning.

SCHIFF: Thank you, George.

STEPHANOPOULOS: The Roundtable is up next. They're going to take on the political fallout from this week's strike on Syria, plus all that talk of a big staff shakeup in the White House.

(COMMERCIAL BREAK)

STEPHANOPOULOS: The scene on Friday as the Senate voted to confirm Judge Neil Gorsuch to the Supreme Court, one day after Majority Leader Mitch McConnell broke a Democratic filibuster by unleashing that nuclear option.

So what does that mean for the future of the Supreme Court and the Senate? Our "Roundtable" is going to weigh in when we come back.

(COMMERCIAL BREAK)

(BEGIN VIDEO CLIP)

TRUMP: I am flexible. And I'm proud of that flexibility. And I will tell you that attack on children yesterday had a big impact on me. Big impact. It was a horrible, horrible thing. And, it's very, very possible, and I will tell you, it has already happened, that my attitude toward Syria and Assad has changed very much.

(END VIDEO CLIP)

STEPHANOPOULOS: That is President Trump in the Rose Garden on Wednesday. Let's talk about it on our "Roundtable." Joined by our chief political analyst Matthew Dowd, also author of the new book, "A New Way," we've got it right here. Republican strategist Kristen Soltis Anderson. And Democratic pollster Cornell Belcher, author of "A Black Man in the White House."

And, Matthew, let me begin with you with the president talking about his flexibility, showing great self-awareness right there. But I think the real question now is everybody is sort of guessing about what is going to come next, what the White House strategy is.

MATTHEW DOWD, ABC NEWSCHIEF POLITICAL ANALYST: Well, you know, everybody can -- or everybody, most -- there's unanimity around the idea that Assad is a despicable character and what he did is a crime against humanity.

But the problem is there doesn't seem to be any strategy. And as I listened to all those interviews before, there definitely isn't agreement among all the people surrounding the president.

They have to come up with a strategy. And usually, you like to do that before you take action. That would be great thing.

But is it regime change? I don't know if it's regime change or not. Is it that we're going to enter into places where bad things are happening around the world to human beings? That would be great. But there's a lot of places around the world where that is going on.

And finally, a president isn't made. This is what all the discussion that happened in the media after those strikes. A president isn't made by these one-off decisions. He's not become president, doesn't become a leader by decisive actions and this.

Presidents are made by what is the long-term strategy and what is the long-term result.

STEPHANOPOULOS: And Kristen, the president already facing some backlash from some of his most loyal, most fervent supporters during the campaign, who took what he said about staying out of Syria, it's going to create a World War III, took it very seriously.

KRISTEN SOLTIS ANDERSON, REPUBLICAN STRATEGIST: That's right, you had, especially online, a lot of folks from the alt-right movement, which was a piece of Donald Trump's coalition, albeit a small one, who are very vocally upset about this. And it's really raised this question of, in policy, do politicians lead voters or does it go -- does it got a different direction? Do politicians take positions and then voters decide, well, I'm going to follow that leader? Or do people decide which leaders they like based on the policy positions?

Here, if Donald Trump is shifting very dramatically his position on foreign policy, do Republican voters go along with him or does he lose some of his own party?

STEPHANOPOULOS: And Cornell, one of the big impulses certainly driving President Trump is he -- he generally is going to do whatever the opposite of what President Obama did. President Obama drew the red line, didn't act. President Trump is going to act. And you did see this unusual praise coming for President Trump from some of Obama's past security advisers who'd also thought he should have struck then.

CORNELL BELCHER, DEMOCRATIC POLLSTER: Well, look, when you listen to the -- Secretary Tillerman's interview, I didn't know -- until you got to Mexico, I thought you might have been talking to John Kerry. I mean, there doesn't seem to be a great deal of change here.

Look, President Obama asked Congress for the authority to strike. And of course Congress decided not to. Back then in 2013, you had majority of voters who said, quite frankly, the president should ask for the authorization and then the majority of voters said, well, we shouldn't get involved.

And I think what's really interesting beyond sort of this week's back and forth is what's going on with Rand Paul and Senator McCain? I think this is a very important debate, what's going on right now. Whether or not a president who can see something on television, change his mind, and then send missiles because he changed his mind -- I think is a really important question.

(CROSSTALK)

STEPHANOPOULOS: (INAUDIBLE) is Rand Paul isolationist, John McCain interventionist.

And you get the same thing playing out inside the White House, Matthew Dowd. Fascinating stuff going on this week, this infighting. Steve Bannon, off the National Security Council. Of course he represents the alt-right populous wing of the Donald Trump White House. He's in a feud with Jared Kushner, who was a Democrat before this campaign, perhaps the president's most influential adviser right now. Reince Priebus in the middle representing establishment Republicans.

And when you have a flexible president like that, these fights mean so much more.

DOWD: The three faces of Donald Trump. Right? This is not -- this is not Reince Priebus' problem, or Steve Bannon's problem, or Jared Kushner's problem. This is Donald Trump's problem because Donald Trump hasn't come up to what is the fiber of his politics (ph)? What is the fiber of his principles? What does he stand for? And then everybody else in the administration basically succumbs to those principles. Like Ronald Reagan. Some people liked Ronald Reagan. But everybody basically had to buy into his vision and what his principles are. I don't think Donald Trump has --

STEPHANOPOULOS: Though Reagan had a lot of flexibility on tactics.

DOWD: He had a lot of flexibility, but that's a totally different deal. Everybody knew what the vision was, knew what the strategy was, knew what the policies were, and everybody was for them. Donald Trump, I think, all of this is a reflection of who Donald Trump is and the fact that there's tons of conflict in it.

STEPHANOPOULOS: How does it play out -- I imagine it must have a lot of Republicans worried?

SOLTIS ANDERSON: Well, this is a concern for a lot of really conservative Republicans during the Republican primary, back a year or longer ago -- was Donald Trump actually going to be a conservative president? Or do things that Republican voters on the right really liked?

You saw this play out during the health care debate now about where does Donald Trump fall on --

(CROSSTALK)

STEPHANOPOULOS: Yes, but I can imagine Donald Trump looking at that and saying, yes, I tried that. It didn't work. We lost.

SOLTIS ANDERSON: Well, and I think that's going to have some interesting implications for the rest of his domestic agenda.

But I think Donald Trump is not confined to any particular doctrine or ideology. And if you are a Republican who's very conservative, you have to be feeling a little nervous about this White House right now. Is he moored in the same principles you are? It's becoming to become clearer and clearer that he's not moored in particular principles, that he's more pragmatic in going with whatever the moment calls for.

BELCHER: But this is the political problem for Donald Trump, right? He got 46 percent of the vote. And a lot of that was blue collar, you know, voters who are struggling, who bought into this America First. And America First isn't intervention, right?

We spent more on that missile strike than what it would've taken to fix the Flint water problem, right? So you have a whole cadre of blue collar struggling Americans who rejected this from typical Republicans, and the moment he starts sounding like George Bush and Dick Cheney, I think he has a political problem.

STEPHANOPOULOS: Well, actually -- but I heard from Secretary Tillerson maybe the policy isn't decided yet, Matthew Dowd, is that Donald Trump is not all that eager to get in there all that deeply.

DOWD: Well, you can tell that from it. He did -- he said I'm going to be decisive. He launched the missiles. But basically there's been pullback ever since that -- that evening of the strike. It's all been pullback. No, no, no, we're not going to -- we're not interested in removing Assad externally. No, no, no, we're not interested in more military action.

And the other part of this, which is obviously been highlighted this, is where does Steve Bannon fit in all of this? What is his policy on all this?

I disagree with the premise that somehow removing Steve Bannon will make White House better. We're on the day, the Masters Sunday. It's going to be a great Sunday for the Masters tournament for all of us who watches it. But it's like, as if somebody says, somebody is playing on the golf course and they say, well, that club is bent, or that club is crooked, and therefore, I lost the tournament because of the club.

No, you lost the tournament not because of the club, which is Steve Bannon, you lost the tournament because of your own playing. Donald Trump is not going to solve any problem by removing one part of this White House.

STEPHANOPOULOS: And I wonder -- go ahead.

SOLTIS ANDERSON: The political implications of, say, a Bannon being the first person out, or whichever of these Trump's advisers are the first person out, is we are now in this moment where there is polling data on what people think about certain of Trump's senior advisors. And among Republicans, only 23 percent have a positive view of Steve Bannon. The rest either say they don't know who he is, or they have an unfavorable view.

So, for a lot of Republicans I think right now the idea that removing one of these advisers is going to cause a massive drop in his support I just don't...

STEPHANOPOULOS: No, but it's certainly true that every member of the staff with the possible exception of Jared Kushner and Ivanka Trump are dispensable.

But, Cornell, you know, that's just a fact in all White Houses. But coming out of this, the whole issue in the Senate with the nuclear option and the confirmation of Judge Gorsuch is going to be Justice Gorsuch, I wonder if the whole idea, which some had held out hope for early on in the Trump administration, that there was going to be some kind of grand compromise with Democrats on big issues like infrastructure. That seems dead now.

BELCHER: I think it's really hard. And, you know, I think when you look at what's happened in the Senate -- and I'm sorry, I think you have to put Mitch McConnell front and center of a lot of the dysfunction that you have seen happening and the partisanship that you've seen over the last couple of years.

STEPHANOPOULOS; It's been building for an awful long time.

BELCHER: Well, no -- but, George, this is someone who said, my top priority is in fat to make sure that President Obama is one term. This is someone who blocked more of President Obama's nominees than have been blocked in history. This is someone who said, you know what, I'm the guardian of gridlock.

When you look at what this man has done I think it goes a long way to say that he's front and center.

STEPHANOPOULOS: I'm afraid...

DOWD: ...is also responsible for this.

STEPHANOPOULOS: There's a lot of people responsible. That's going to have to be the last word right now. We'll be right back.

(COMMERCIAL BREAK)

STEPHANOPOULOS: That is all for us today. Thanks for sharing part of your Sunday with us. Check out "WORLD NEWS TONIGHT". And I'll see you tomorrow on "GMA".