DW: What is your take on what you've heard this morning from Russian Prime Minister Dmitry Medvedev (pictured), British Foreign Secretary Philip Hammond, US Secretary of State John Kerry, Russian Foreign Minister Sergey Lavrov, German Foreign Minister Frank-Walter Steinmeier and French Prime Minister Manuel Valls?

Nicholas Burns: I think the dominant theme this year is Syria. The Russian government has been bombing civilian areas, including the city of Aleppo, indiscriminately, with massive loss of life. And frankly that the West is not in a strong position to stop it, because we elected not to be significant players in Syria. We've avoided engagement there, and that left the field open to Russia. To see the speech of Prime Minister Medvedev - I thought it was a cynical speech, because they profess to have peace in mind and yet they are pouring gasoline on the fire.

I thought Secretary Kerry, Foreign Minister Steinmeier, Foreign Minister Hammond all tried to speak in more positive terms about what we can do if we're united. The big question is: Will Russia honor this agreement to stop the bombing and allow humanitarian supplies in? So, the Syria question is dominating this meeting.

How optimistic are you that this peace plan for Syria will be implemented? How realistic is the cessation of violence within a week?

Since (Syria's) President Assad has not yet agreed to a ceasefire and some of the rebel groups haven't either - and Foreign Minister Lavrov seemed to indicate in his remarks here that he's upset that some people are trying to convince Russia to stop bombing - I think that I'd be surprised if this agreement was fully implemented. And that's a tragic situation for the people on the ground.

What's the way out of this, then? Where do we go from here?

I think continued pressure on the Russian government to stop what it's doing - stop the bombing. The Russians have been a very violent actor in Syria. The West needs to be stronger. I think the United States needs to provide stronger leadership to the trans-Atlantic community and help Europe more with the refugee problem. I think it's been a fascinating conference. There's a lot to think about, but Syria certainly is front and center.

Nicholas Burns served in the United States government for 27 years. From 2005-2008 he was the Under Secretary of State for Political Affairs. He has also served as the US Amassador to NATO, Amassador to Greece and State Department spokesperson. He is now working as a professor of international relations at the Harvard Kennedy School of Government.