Areas of "difficulty and difference" remain between Russia and the US ahead of key talks on the crisis in Syria.
A US state department spokesman played down chances of a deal at the talks, to take place today in Geneva.
Russian Foreign Minister Sergei Lavrov earlier met US counterpart Hillary Clinton, and said there was a "very good chance" of finding common ground.
Meanwhile, more than 100 people have been killed in Syria since Thursday.
At least 25 people, including 11 civilians and 13 soldiers, died yesterday, and there were 117 civilian deaths on Thursday.
Meanwhile, Syrian President Bashar al-Assad said he would not accept any solution to his country's crisis imposed from outside.