US Secretary of State John Kerry has described as "constructive" talks with his Russian counterpart Sergei Lavrov on securing Syria's chemical weapons.
The two men began a second day of talks in Geneva by meeting UN-Arab League envoy Lakhdar Brahimi to discuss the wider issue of peace in Syria.
Talks between Mr Kerry and Mr Lavrov on the weapons issue began on Thursday and could continue over the weekend.
Mr Kerry said they were working hard to find "common ground".
The BBC's Paul Adams in Geneva says this is a moment of diplomatic momentum over Syria which has not been seen for a couple of years and both parties want to make the most of that.
Russian President Vladimir Putin on Friday called Damascus's decision to join the Chemical Weapons Convention "an important step towards the resolution of the Syrian crisis" and said it showed the "serious intention" of President Assad "to follow this path".