Russia hopes to avoid the "worst scenario" in the situation in Syria's Idlib, Kremlin spokesman Dmitry Peskov said Friday.

"The situation in Idlib is really very alarming and it causes deep concern. This situation is always a topic of discussion between the Russian and Turkish sides," Peskov told reporters at a daily briefing.

Militants that carry out aggressive actions against Syrian government forces in Idlib should be neutralised, he noted.

Peskov said that the possibility of holding a summit of Russian, Turkish, German and French leaders on Syria is being discussed, though there are not yet any concrete agreements.

On Thursday, Russian President Vladimir Putin discussed the situation in Idlib with French President Emmanuel Macron and German Chancellor Angela Merkel by telephone.

Also on Thursday, Syrian government troops backed up by Russian warplanes repelled several massive attacks by militants supported by Turkish artillery fire in Idlib.

Russia's Su-24 attack aircraft struck the militants, while the Russian military urged Turkey to stop supporting the militants and halt supplying weapons to them in order to avoid future incidents.