Updated

The U.N. envoy for Syria says he's hoping upcoming peace talks in Geneva produce new momentum and that much depends upon the position the U.S. decides to take.

Staffan de Mistura said Sunday "the big question mark is where is the U.S.?" He told the Munich Security Conference "we have to push for momentum" at the talks starting Thursday.

But State Department diplomat Brett McGurk says "people will be disappointed" if they envision the U.S. suddenly finding a new "tool in the toolkit."

He says "I don't think the U.S. will come in with a one-size-fits-all solution, because there isn't one."

Syrian National Coalition President Anas al-Abdah said the opposition is "fully committed and prepared to negotiate a political solution," adding "we have a glimmer of hope."