Transcript for Bernie Sanders: 'People Are Responding to Our Message'

Let's go straight to senator Bernie sanders. Senator, good morning. You saw those new poll Numbers, is Hillary Clinton's campaign in trouble? Well, I don't know if her campaign is in trouble, but our campaign is doing great. It's not just in Iowa, it's in New Hampshire, I think people are responding to our message that something is wrong when the middle class of this country continues to disappear, people are working longer hours for low wages, and almost all of the new wealth and income is going to the top 1%, that's not the type of country, not the type of economy that the American people want or deserve, and I think they're prepared to support somebody who's going to take on the billionaire class and make an economy work for ordinary people not just for the people on top. Well, senator sanders, Hillary Clinton has lost about a third of her supporters since may, but the polls don't show those supporters, a significant number, are not heading your way, why not, given what you said? Well, the poll that I saw said that there was massive enthusiasm for the message that we're delivering and the vast majority of people who are voting for me in that Iowa poll, I'm not necessarily anti-hillary Clinton, they're pro-bernie sanders, and they want a candidate who's not dependent upon super PACS. A candidate who's prepared to turn over this disastrous citizens united. A candidate help the united States leave the world in combatting climate change, make college affordable to all people. I have to tell you, Martha, I think the gains that we are seeing and the enthusiasm and the huge crowds that we are seeing, this is not anti-hillary Clinton, this is pro-bernie sanders and pro a message that says, enough is enough, this country and our government belong to all of us. Not just a handful of very wealthy people. Senator sanders, this morning, again, we know you have been voicing great concern about the middle class, the cost of college, climate change and yet, there are two issues that are entirely missing from your campaign website, and those are issues of national security and foreign policy. Don't you feel these are issues that a president should be very concerned about? Absolutely, Martha, and you know, in all fairness, we have only been in this race for 3 1/2 months and we have been focusing quite correctly, as you have indicated, on the economy, on the collapse of the American middle class, on massive income and wealth inequality. But you're absolutely right. Foreign policy is a huge issue. We'll spend more time on that. You're looking at a senator and a former congressman, and as a congressman I voted against the war in Iraq, which I think will go down in history as one of the worst foreign -- foreign policy blunders that we have ever seen leading to the enormous destabilization of that region right now. But the issue of foreign policy, how we bring the world together, our allies together, not to do it alone to take on Isis, to deal with the other threats and problems around the world -- Senator sanders, you brought up the Iraq war. You also voted against the first gulf war in 1991. When saddam hussein had invaded Kuwait. You did not support air attacks after chemical attacks in Syria, you did support the initial invasion into Afghanistan, so, can you tell me what your criteria is for the use of force? Yes, good question, a fair question. Look, I think historically, in too many instances, the united States has gone to war often unilaterally when we should not have. I think my vote against the first war in the gulf region was the right vote, I think we could have gotten saddam hussein out of Kuwait in a way that did not require a war. Certainly my vote -- Even though he had invaded Kuwait? But, the point was, you had the whole world united against him, Martha, do we need to go to war in every instance? Can we bring pressure of sanctions and international pressure to resolve these conflicts. Look, I'm supporting president Obama's effort to make certain that Iran does not get a nuclear weapon. But I get very nervous about my republican friends who keep implying that the only way we can do that is through war. War is the last resort not the first resort. There are times when you have to use force, no question about it. But that should be the last resort -- Is that we're only attacked? If you look at your record, you supported the invasion into Afghanistan after we were attacked. Is that the only time you would support it? No, not at all. Not at all. I think using our military is an option, obviously, that we will always have under certain circumstances. But it is the last option. I applaud the president for trying to make certain that we stop Iran from getting a nuclear weapon but we do it in a way that does not require war. The second point that I would make is, the United States can't do it alone. In the middle east, Saudi Arabia has the third largest military budget in the entire world. They're going to have to get in and take on Isis as well as other countries in that region. The United States should be supportive. We should be working with other countries. The United States can't always be the only country involved in these wars. Let me go back to the Iran agreement that you brought up and your support of that agreement, can you imagine Iran or Russia signing some sort of agreement in the future, giving your record on your reluctance to use force, because there is always that threat of force, but they may look at you and say, Bernie sanders wouldn't do anything about this. Well, I think they would be making a very, very big mistake. The United States should have the strongest military in the world. We should be working with other countries in coalition. And when people threaten the United States or threaten our allies or commit genocide, the United States, with other countries, should be prepared to act militarily. But I think when we look at our recent history, again, especially the war in Iraq, I think history will record that as a terrible mistake which has led to massive destabilization and many other problems. So, yes, there are times when you have to use military force, no question about it. I am prepared to do that. Would you do away with the drone program? Would you do away with the drone program? Because you have had clearly problems with that. You didn't vote for the cia director because of the drone program and how it was run. Martha, what you can argue is that there are times and places where drone attacks have been effective. There are times and places where they have been absolutely countereffective. And have caused more problems than solved. When you kill innocent people, what the end result, people in the region become anti-american, so, I think we have to use drones very, very selectively and effectively. That has not always been the case. Okay, thank you very much,

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