Russia's government strongly rejected UN report on war crimes in Idlib.
Kremlin spokesman warned Turkey that Russia can not guarantee the safety of Turkish planes over Idlib.
Russia foreign minister Sergei Lavrov said: Turkey and Russia did not reach an agreement over Syria's Idlib in their negotiations.
Russia's envoy on Syria said: The US abuses Syria's natural resources.
Turkey has supplied an array of Syrian opposition fighters it supports with weapons to help them try to repel a major Russian-backed assault.