Russian President Vladimir Putin (L) meets with US President Barack Obama on the sidelines of the G20 Summit in Hangzhou, China, September 5, 2016. [Photo/Agencies]

HANGZHOU, China - US President Barack Obama and his Russian counterpart, Vladimir Putin, are meeting here Monday in this eastern Chinese city on the margins of the 11th G20 Summit.

The United States and Russia have been trying to reach a deal over the Syria crisis. Obama said Sunday that the two sides still have "grave differences," but there is still possibility "to make some progress."