TAPPER: On Iran and the Saturday meeting with the P-5 plus one, Iran has said that they reject preconditions for the meeting. Will the meeting go ahead even with Iran rejecting preconditions?

CARNEY: There are not - I mean, we - the meeting we look forward to - and we believe it's important that this meeting takes place in Istanbul. What we've agreed to is to launch a new round of talks, and we're pleased that these talks are happening. And the talks - at the talks, we will obviously, as will our partners, address the international community's concerns with Iranian behavior regarding their nuclear program.

You know, we're looking forward to these talks creating a conducive environment for concrete progress. I mean, our - you know, we are committed to preventing Iran from acquiring a nuclear weapon.

Iran needs to take steps to demonstrate that they, in a verifiable way, do not want to and will not pursue the acquiring of a nuclear weapon.

So we're not drawing lines in the sand here about - before the meeting takes place, but we are very clear-eyed about what Iran needs to do in order to fulfill its international obligations and be able to reassure the international community that it is not pursuing nuclear weapons. And that is the crux of the problem.

Regardless of what the Iranians have said about what their intentions are, no one on the international stage has faith in those assurances. So they - we need concrete steps taken by the Iranians to assure that they will forsake their nuclear ambitions - weapons ambitions.

TAPPER: And with Afghanistan and the night raids, can you precisely explain what the U.S. has agreed to in Afghanistan?

CARNEY: Sure. There is a memo of understanding, which General Allen signed and presided over, that is the product of a negotiation with the Afghan leadership that allows us to go forward with our plans for transitioning to Afghan security lead. This was an issue of particular interest and concern on behalf - on the part of the Afghans. And what this will do will ensure that the Afghan forces have the lead in so-called night raids.

As you know and have reported on, the night raids are a source of concern for the Afghans. We understand that, and we have worked out an agreement that we think is very important that will allow necessary actions to continue to take place as we implement our policy. It will also allow us to move forward on the strategic partnership declaration and will allow us to move forward on the overall strategy in place, which includes a drawing down of U.S. forces as we transition to Afghan security lead.

TAPPER: And there are exceptions to the rule, right, I mean, when it comes to Afghans taking the lead on the night raids?

CARNEY: Well, I would refer you to the Defense Department for the specifics, but I think that the Afghans will have the lead in the night raids. We will, you know, ensure that - you know, part of the importance of this agreement is to put it in place so that we can continue to move forward on all the other aspects of implementing the mission.

-Jake Tapper