Transcript for Secretary of state makes historic visit to Moscow

Hey everybody. Here in New York the late. US secretary of state Rex tellers and historic trip to Russia experts is that they're out that taking the post top. Aren't hearing is there in Moscow following Jerry for us Mary thanks for being. You bet. So I love being in Moscow related. If this were looked beautiful places. Anymore it is stunning backdrop in the US. Conference the First Act with his counterpart. Russian foreign minister Sergei Lavrov sort of surreal moment long time coming hiding it. Well that was a big moment it was a big moment for Rex Tillerson but much more for the big moment for these two countries that Phillips and himself that. It is opening comments. That trust between Russia and the United States has reached a low point and he said for the two largest nuclear powers in the world. That is the relationship that cannot continue and so what you heard from both with an effort. That kind of stepped back from them brinksmanship. That has been. Being bandied back and forth between Moscow and Washington. Since the US launched its missile strikes against that air bases theory after the chemical weapons attack Syria one of Russia's closest allies. The headline from here is that bald. Russia and the United States out of this meeting have agreed to a US led investigation of what really happened. In. Should code in what happened in that chemical weapons attack. Who was responsible what was used now all word of caution the last time there was the UN. Investigation into chemical weapons in Syria. Was back after the 2013. Attack outside Damascus that concluded. That chemical weapons were used lightly by the fearing government and Russia. Rejected that finding but that is that is a way forward here from this. And Terry both secretary Tillerson and foreign minister lap brought there can sort of repeatedly talked about. How they have to work together how they have to find common ground Tillerson himself started listing all the points on which they do see Ida high. But in their answers during the question and answer portion it became clear that fixed a lot of daylight between the two in terms of how they see what's happening in Syria. Absolutely that the common ground it is that as as Sergey Lavrov the foreign minister of Russia said. Defeating ice is this something that they both agree on that the United States and Russia especially on president trump who started. Banked his foreign policy in some ways of bringing Russia. I uniting with Russia in the fight against. What he calls radical Islamist terrorism and that was reaffirmed here today however on the other side and this was really Barry striking moment. The secretary of state of the United States Rex Tillerson said that the government in Syria the Assad regime. That its reign is over he said it's days are numbered. It is no longer seen as a legitimate government in Syria by the world community. And it is time. That there's no place in in serious future for the Dodd family. Altogether that atom warmed the hearts of many opponents of Bashar Al Assad and may in fact be morally right. But there is no means to that end in the United States policy at this moment it is and the so it's essentially without actually. Finding a way to get a thought out and the foreign minister Russia's Sergey Lavrov gave no indication that that is a priority for Russia. He didn't back aside but he certainly didn't sign on to yell let's get rid of this size so it it was have a dangerous thing. Because great great powers if they put their credibility on the line we're gonna have regime change. She generally follow up and they don't they they lose credibility that's the risk that Obama found in Syria I think Rex Tillerson just double down. And Terry if you mention their Lavrov repeatedly saying he's not there to level any accusations he's nor is he dared to exonerate anyone but again and again. When that chemical attack came up. In the press conference the one that prompted missed president trump to launch the air strikes. The Russian foreign minister repeatedly saying we needed investigation we need to know more as he said now they have agreed to go forth with an investigation but. Tillerson language was much more precise and much more strongly think we have his sound -- its answer to that question right now. Oh I think the perspective from the United States supported by. The facts that we have. Are conclusive. That the recent chemical weapons attack. Carried out in Syria was planned. And it was directed NX acute advised Syrian regime forces. There require confident. This is just the latest in a series of the use of chemical weapons by the sought region. And notwithstanding. Their use in all more than fifty occasions. Of chlorine bombs. The cluster bombs and other types of weapons that are intended to maim. And killed in the most terrific Reuters. So I think the characterization. Is one that. President Asad. Has brought on himself. Carry this dovetails of course is what we're hearing from the UN ambassador Nikki Haley here basically accusing Russia of covering up. What happened at that chemical attack site in Syria so if they are confused US message going here. Well it made it looks to me like the US as Juarez. We kicked out for what they've status thing it a policy. That it is concluded. To the satisfaction the United States government that the if not Rahim used chemical weapons that Lavrov Gordon that as evidence at gifted. He said that nobody actually got in there and took a look at the site. It entirely true Turkish doctors took a look at victims and and said that they concluded that Sarin gas was used. The British ambassador to the United Nations today said that British chemical weapons act experts have looked at soil samples. And sad chemical weapons apparently were used. But Lavrov and the Russians don't agree on that I think it's the United States is. They talked about today Nikki Haley at the United Nations that they've state Tillerson here. Make it. But haven't come back it up this notion. That we know that chemical weapons were used that it has no future and area. Where Russia is still standing behind him. To think nothing of Iran which is much more closely allied with its odd personally. That month. Terry this wraps a very unfair question but where is the common ground here and we're hearing again and again from the US. That Syria cannot have a future peaceful future with the aside and Lee in power we heard again and again from lap brought there. That they they don't want to get in the business of regime change he kept citing Iraq and Libya as previous exam. All's gone horribly wrong. How do these two countries possibly move forward on the same page. Well that's a good question I think a answer boils down to sequencing. One of these Lavrov said was L one problem at a time let's cleared. Syria. These G Heidi terrorists. Let's fight ices. And and defeated. And then let's get this that whatever comes next. Second their state Tillerson said as well that there's no. Particular moment in time when these things have to happen but that when the political future of Syria is the side of the -- should be there and he added if Russia. That can really help make that happen so it seems that their charm once again do they get that common ground. The president trump articulated in this campaign that they Russia the United States can fight prices together in Syria. And then work out whatever the future of Syria is now that of course leaves the appalling suffering. Of the Syrian people. Under the Asad regime and under the various violence acts in groups that are that are Terry that country apart to continue. While these great powers take care of their problems in their country but that seems to be the common ground sequence. Terry while I've got to him for a let you go and this is not the only four in front on which president on its actively working and concerned with high on his list of course. Is North Korea. Others into the sequence at tweets he's been putting out recently most recently this one we know after the White House confirmed. He did in fact have a call with the president of China concerning as he wrote after he treated the menace of North Korea. But what does this reveal to us abouts president trumps policy or approach moving forward with North Korea. That it's heating up I think that the best thing we can say it clearly on the president's mind. The president's Twitter feed is now almost a security risk you can look at it. That at a time when North Korea was not in the news cycle although no Fox News report on North Korea. Also they treat these red twinkies rather alarming thinks about how China's got to put pressure north where I'm gonna. It would take care the problem myself. That might suggest that he just had a pretty alarming briefing. All or that he's thinking about. A decision point. Around North Korea in a way that probably isn't helpful to reveal to the world. But whatever the case what's clearly going on is that he was handed a terrific problem. By a President Obama could not solve it just as George W. Bush could not solve it. That this is. An isolated and dangerous criminal regime bent on getting nuclear weapons capable of hitting the United States and that it's something. That no American president George W. Bush. Barack Obama Donald Trump will accept that it's dangerous way. Kerry. ABC's chief foreign correspondent thanks so much for being with us from Moscow tonight. That. And thanks to all of you for watching of course you can go to abcnews.com. Anytime for more on the story and others they right here for your latest live news for now I'm on an Abbas.

This transcript has been automatically generated and may not be 100% accurate.