So there are two separate tracks. One track is for the Syrian government and the opposition that is interested in a peaceful future of Syria to come together for national unity, for the political process. At the same time, it is a requirement for everybody to stop supporting the extremist groups, to stop allowing them safe passage, to stop allowing them to receive weapons, to stop allowing them to receive financial assistance, and to come together in actually fighting them.

I think we are making an assumption that that is the outcome of the negotiations. I think President Assad will be prepared to accept whatever the outcome of the intra-Syrian dialogue and the decision of the Syrian people is. But people are trying to decide and determine the outcome of the negotiation before even we agree to start the negotiations.

The United States wanted to send its trained rebel groups to Syria to fight ISIS. Out of twenty-five hundred rebels they had trained, only seventy accepted to go to Syria to fight ISIS. Everybody else wanted to go to Syria to fight the government. So you've got to wake up and smell the coffee. . . . The rebel groups have not fired a shot against ISIS.

Tehran believes it's none of our business or anybody else's to decide the future of personalities in other countries.

Understanding that these statements do not represent reality, we should not be threatened by the language that he has used.

The nuclear program is not the only issue dividing Iran and the US. Iran's role in the region is also creating conflicts. For example, you support the Shiite Houthi militias in Yemen whereas the US is on the side of the coalition led by Saudi Arabia.

I think the most important challenge that remains is this mentality in Washington that sanctions have been an asset, and some people want to find even an excuse to keep them or an excuse to reintroduce them. I don't know whether they've looked at the record of how sanctions actually produce exactly the opposite of what they wanted to produce.