Russia hopes for a peaceful resolution of the situation in Syria's rebel-held province of Idlib but believes it is up to Turkey to separate Islamist militants from the moderate opposition, Russia's Syria envoy said on Tuesday.

"We are saying the situation in Idlib should be settled most preferably in a peaceful way. It is possible to abstain from using military force," Alexander Lavrentiev told reporters after talks in Geneva with U.N. envoy Staffan de Mistura.

"Idlib province is...a sort of zone of responsibility of Turkey; it is their responsibility to separate the moderate opposition from the extremists, from Jabhat al-Nusra and other groups, other terrorist groups," he said.