JUDY WOODRUFF: Secretary Kerry, welcome. Thank you for talking with us.

JOHN KERRY, Secretary of State: It's my pleasure.

JUDY WOODRUFF: So you've put a lot of effort into negotiating this framework agreement, spent months, if not years on this. People look at this and they see all that effort and I think one question is, is it going to take even more work to get the remaining unresolved issues figured out, or is the hardest part behind you?

JOHN KERRY: It's going to take more work, but it may also be that the hardest part is behind us. Because the framework has really crossed a barrier, if you will, but the details are going to be tough. And coming down to the last comma, the last crossed T, I'm confident will be, probably, as difficult as the last couple of days were in the framework.

JUDY WOODRUFF: Well, before we talk about the details, I want to ask you something. I think I just ought to clarify, for the American people, what this is. Is it correct to say that this is really about, not about denying Iran a nuclear weapon, but delaying the day when they can have one? And delaying it really by only a matter of months?

JOHN KERRY: Absolutely not. Not in the least. No, it is not just about that. It's about denying them a nuclear weapon. And the reason I can say that with confidence is that we will have a sufficient level of transparency of inspection, so accountability of tracing of uranium and following the production of their centrifuges, of knowing what is happening in their program, that if they began to increase their enrichment in order to be able to move to create a nuclear weapon, we would know immediately and be able to take actions. So I don't agree with that assessment. This is a guarantee that for the next 15 to 20 years they won't possibly be able to advance that program and then, when they become a more legitimate member of the non-proliferation community and subject to lifetime inspections and investigation, we will have accountability.

JUDY WOODRUFF: But it is said that right now they have a breakout capacity, three to four months, and at the end of this agreement it would be a year. Meanwhile, they have enrichment capacity, they have the ability to do research and development on these so-called advanced centrifuges, enriching uranium where they could even potentially, and the president himself has acknowledged this, create a weapon within, almost instantly.

JOHN KERRY: Well, let me describe where we are today, Judy, because it's important for people to think about where is the starting point here. When I became secretary of state, they had 20,000 centrifuges, a very large stockpile of enriched uranium at 20 percent and they were moving in the direction of really threatening perhaps go down and get bomb. Now, they no longer have that 20 percent enriched uranium. It's been reduced to zero. It's gone. They no longer enrich above a small percentage, 3.5 percent. They no longer have the ability to break out in the same period of time as when we started this.

When President Obama became president, they already had enrichment; they already had mastered the fuel cycle. So in the years preceding that, they were edging up and up and up constantly. Now we're going the other way. We're rolling the program back and putting in place a very strict set of transparency and accountability measures that will allow us to know what is happening. And it is not accurate to say it is only 10 years. Some measures that are in this deal go for 15 years, some go for 20 years, some go for 25 years, like the tracking of uranium. That's a 25-year tracking of uranium. From mining, to milling, to the yellow cake, to the gas, to the centrifuge, the waste. We'll follow every part of that. And there are lifetime provisions here, “forever provisions,” that they have to adhere to.

JUDY WOODRUFF: Well, let me ask you about some of the details which you mentioned: Inspections.

The president has said these will be the most intrusive inspections, robust inspections ever. Others have said it'll be anywhere, anytime. The Iranians are saying no, it won't be on military bases and there are going to be limits. Which is it?

JOHN KERRY: We're going to have a very robust inspection system. We have a means-of-dispute resolution that will permit us to be able to resolve questions if there are any unresolved issues of access.

They have agreed to abide by what is called the additional protocol of the nonproliferation treaty. That protocol requires participating states to adhere to a higher standard and if they don't, Judy, then the sanctions can, and will, come back. For a certain number of years that will happen automatically, but I can assure you that if Iran were then to suddenly move to try to advance this program beyond what would be normal for a peaceful nuclear power, the whole world will respond just as we have now and sanctions would be re-imposed.

JUDY WOODRUFF: But aren't there real questions about that? The administration is calling them “snap-back sanctions,” but in effect, you have to go back…

JOHN KERRY: Well, that's for a period of time. No, we don't have to go back. There's no veto power capable. It's an automatic process under a specific procedure which will be spelled out in the course of the final deal. I'm not going to go into it all now, except to say to you that we're not going to sit there and carve out a pretense here. We have told people, and we're serious about it, that there will be an ability to have accountability in this inspection regimen, and there will be.

JUDY WOODRUFF: Still, another issue; the International Atomic Energy Agency has said for a long time that it wants Iran to disclose past military-related nuclear activities. Iran is increasingly looking like it's not going to do this. Is the U.S. prepared to accept that?

JOHN KERRY: No. They have to do it. It will be done. If there's going to be a deal; it will be done.

JUDY WOODRUFF: Because it's not there now.

JOHN KERRY: It will be done.

JUDY WOODRUFF: So that information will be released before June 30th, will be available.

JOHN KERRY: It will be part of a final agreement. It has to be.

JUDY WOODRUFF: Congress, President Obama is now saying that there may be a role for Congress in signing off on the deal as long as Congress doesn't materially change anything. My question to you is, if you were Sen. Kerry, you were chairing the Senate Foreign Relations Committee and it were a different president, wouldn't you be insisting that Congress have an up or down say on this?

JOHN KERRY: Judy, one of the things I learned a long time ago, and I particularly know now, is don't answer hypothetical questions. So I'm not going where I don't have to be. And I left the Senate. I'm not there now, I'm secretary of state. And the president is absolutely correct in making sure that what Congress does not assault presidential authority and the Constitution, and doesn't destroy his ability to be able to negotiate this final deal. That's critical. And the president has said, if the bill is what it is today, written the same way it is today, then he'd veto it. But if it's changed, and adjusted and reflects the respect for the Constitution, then the president's prerogatives, while at the same time embracing congressional oversight and review, fine.

One other thing I'd say to you is, Congress is going to vote. Congress can vote any day it wants to. You know the majority leader has the right to bring something to the floor and have a vote. So this is really, I think, a little bit excessive. I mean, the truth is also, Congress will have to vote to lift ultimately some of the sanctions which are congressionally mandated. So we all understand the process here, and I think we just need to be serious in a way that does not interfere with the president's ability to pursue the foreign policy interests of our nation.

JUDY WOODRUFF: Some of the other concerns that are now being raised, but assuming this deal is finalized at the end of June and, and the U.S. embarks on this new way forward, doesn't this raise expectations, and there's already a lot of talk about this. The U.S. is going to have to increasingly show its support for those in the region who fear Iran. Not just Israel, but the Arab nations, Saudi Arabia, the UAE, the others, Egypt. In other words, that the U.S. is increasingly obligated to have the back of more nations than it already is supporting and backing militarily.

JOHN KERRY: Judy, let me make it clear: It doesn't take this negotiation to prompt this administration to be there for our friends and our allies. We are there. We have been there. No administration, this is not an exaggeration, no administration has ever done as much as President Obama has done in order to help provide equipment and munitions and defensive mechanisms, other things to Israel. The president has said that's a lead pipe, total guarantee. At the same time, all of our other Gulf-State allies and friends in the region, we have already, long before the discussions with Iran, been talking with them about pushing back against Iran's behavior in Yemen, in Iraq, in Syria, in Lebanon and other places, and that will continue.

JUDY WOODRUFF: Quick questions off today's news: Yemen. Iran has announced it is sending two war ships to the Gulf of Aden, just off the coast of Yemen. Iran says it is not providing military assistance to the Houthi rebels who helped depose the president. Is that something the administration accepts? And what is, and how concerned is the administration about what's going on there?

JOHN KERRY: Well, we're very concerned about what's going on there, and it's just not a fact. … There are obviously supplies that have been coming from Iran. There are a number of flights every single week that have been flying in and we trace those flights and we know those. We're well aware of the support that Iran has been giving to Yemen. And Iran needs to recognize that the United States is not going to stand by while the region is destabilized, or while people engage, you know, in overt warfare across the lines, international boundaries and other countries. So, we're very concerned about it and we will, well what we've made clear to our friends and allies is, we can do two things at the same time.

We have an ability to understand that an Iran with a nuclear weapon is a greater threat than an Iran without one, and at the same time, we have an ability to be able to stand up to interference that is inappropriate or against international law, or contrary to the region's stability and interest, and those of our friends. And we're not looking for confrontation, obviously, but we're not going to step away from our alliances, and our friendships, and the need to stand with those who feel threatened as the consequence of the choices that Iran might be making.

JUDY WOODRUFF: Secretary John Kerry, we thank you very much for talking with us.

JOHN KERRY: Thank you. Appreciate it.