'FOX NEWS SUNDAY' HOST CHRIS WALLACE: Mr. Ambassador, welcome. Thanks for talking with us on a very busy day.

ZALMAY KHALILZAD, U.S. AMBASSADOR TO IRAQ: Good morning. It's nice to be with you.

WALLACE: Will the National Assembly meet its deadline and approve a constitution by tomorrow?

KHALILZAD: I have just come from meetings with the Iraqi leaders, and they tell me they are very optimistic that they will meet the deadline. They have resolved most of the issues that divided them when they started the process. And they've got a couple of issues left, and they are going to meet again late this evening with the expectation that they will achieve success and they will have a draft ready by the end of the day tomorrow.

WALLACE: We'll get to several of those remaining issues in a moment, but if they don't meet their deadline, under the interim constitution, the government falls, and there must be a new election. Is there any way to avoid that?

KHALILZAD: Well, they have another option too, Chris, which is that they could amend the law and give themselves more time.

The TAL, which is the law of the land, does allow an amendment to the law and that they will have more time, but that will require a three-fourths vote of the assembly. I am told by the leaders that they will not exercise that option. That's their current judgment.

But the other option is that, of course, the assembly will be dissolved, and there will have to be new elections, you're right.

WALLACE: You have reportedly played a lead role in drafting this constitution, even submitting written proposals on some of the toughest issues. Is that appropriate in what is supposed to be an Iraqi process?

KHALILZAD: Well, Chris, it's very important for Iraq (search)to have a good constitution.

What do I mean by a good constitution? A constitution that can be helpful to Iraq becoming a successful country. And at the same time, a good constitution here means that there will be broad buy-in from all Iraqis.

Iraq currently lacks an understanding, an agreement, among the major communities about the future. The Sunnis (search), in whose area of a lot of the insurgency is active, they have not participated fully in the political process so far. We need to have a buy-in as far as this new constitution, this new national compact, is all about.

Now, my role has been that when there have been differences between the various forces with regard to a particular issue, and they've asked for my help, I have proposed to them options for bridging the differences between them. Clearly, the choice is theirs, the decision is theirs.

But my role is here to help. I'm happy if they don't need me. But failure is not an option, and if they need my help, I have told them I'm available at any time. And I have provided them some help when they have need it.

WALLACE: I'm told, Mr. Ambassador, that the biggest remaining issue is the role of Islam in the government, including such things as whether or not it will be called an Islamic republic or not, whether Islam will be considered a or the basis for Iraqi law, and also the rights of women.

Where does that stand right now?

KHALILZAD: I think Islam is an issue, the role of Islam. It remains one of the issues that still has not been completely resolved. I think with regard to the name, a decision has been made to call it the Iraqi Republic or the Republic of Iraq.

With regard to the role of women, we have made it clear that Iraq cannot succeed if it moves forward with half of its hand tied behind its back. There cannot be a successful Iraq if this new Iraq discriminates against more than half of its population.

America has invested blood and treasure here, and we stand for certain values, and one of them is equality for men and women. And I believe the new constitution will embrace equality for men and women before the law. This is important not only for Iraqi women and for America, it's important for the world. There's a lot at stake here for everybody in terms of what's going on in Iraq.

On the role of Islam with regards to being a source or the source, I think many Iraqis do not want to see a hierarchy of sources with one, Islam, being the source and others -- other principles of democracies, the principles of human rights as enumerated in the current draft constitution -- that they are also given equal billing in terms of sources of laws for Iraq.

WALLACE: Let's turn, if we can, to the question of Iran, because, Mr. Ambassador, U.S. officials, U.S. military commanders, are saying that Iran has actually been the source of some of the most powerful weapons that are being used against our forces in Iraq.

There's a new report out today that the Iranians have been backing some of the insurgents, paying some of the local militias. And, of course, we all know that some of the top Iraqi officials have long ties to Iran.

How do you stop Iran (search)from being a disruptive force in the new Iraq?

KHALILZAD: Problems that Iraq faces in this difficult transition from being a terror regime to being a successful democratic country is the unhelpful policies of its neighbors, particularly Syria and Iran. We have had reports, and we have discussed them, that weapons are coming across from the Iranian borders, as well as people coming from across the border.

WALLACE: So how do you stop that, Mr. Ambassador?

KHALILZAD: We have discussed this issue. Well, we have discussed this with the Iraqi leaders. They have discussed it with the Iranians.

Iran wants to have good relations with Iraq. We have no particular problem in terms of good relations between Iran and Iraq. But Iran risks the good relations that it has with Iraq if it continues with the current policy, if weapons continue to come across the border of Iran into Iraq.

At the same time, my colleagues in Washington...

WALLACE: But it doesn't sound, sir, as if you have a specific plan to stop those weapons and that interference, that disruption, coming from Tehran.

KHALILZAD: Well, we are working on the issue, Washington is focused on it. This is an issue that goes beyond Iraq, where my focus inside Iraq policies are.

I am working very hard with the Iraqi government so that they can use their influence and leverage with Iran. But the problem has not gone away. Weapons are still coming. People are still coming across that border.

For success here, we need the states in this area to cooperate. The states of the area have to understand that Iraq will succeed. They can delay that success, make it harder, but we are committed. The Iraqis are committed to success. It behooves them to be helpful to this new Iraq, because when Iraq succeeds, it will remember who helped and who opposed their success.

WALLACE: Mr. Ambassador, we want to thank you so much for joining us, and please stay safe over there.

KHALILZAD: Thank you very much, Chris. All the best to you.