Obviously, the United States' own founding principles are self-determination. And I think what the United States and our allies want to do is to enable the Syrian people to make that determination. You know, we've seen what violent regime change looks like in Libya and - and the kind of chaos that can be unleashed.

I think the Russians need to think more carefully about the commitment they made under the chemical weapons agreements to be the guarantor that these weapons would be seized, they would be removed, they would be destroyed. And since they are Bashar al-Assad's ally, they would have the closest insight as to the compliance.

Once the ISIS threat has been reduced or eliminated, I think we can turn our attention directly to stabilizing the situation in Syria. We're hopeful that we can prevent a continuation of the civil war and that we can bring the parties to the table to begin the process of political discussions.

I think the Russians have played now for some time the role of providing cover for Bashar al-Assad's behavior. The alternative explanation that the Russians put forth is simply not plausible.

I think the relationship between the USA and Russia is too important. And it's too important to not find a way to move forward.

Our priority in Syria, really hasn't changed. I think the President Donald Trump has been quite clear. First and foremost, we must defeat ISIS.

Russia and the USA are two largest nuclear powers in the world; it's a really important relationship. How do we start making this work? How do we live with one another? How do we work with one another? We simply have to find a way to go forward.