Moscow: Turkey’s Foreign Minister on Friday warned against a possible Syrian regime offensive on the last remaining stronghold of opposition against Bashar Al Assad, while Russia indicated that it’s losing its patience with the rebels.

Mevlut Cavusoglu, who was in Moscow for talks with Russian counterpart Sergey Lavrov, said that Russia and Turkey should work to separate opposition groups from “terrorists” in the northwestern province of Idlib. He warned against a regime offensive there, saying that it will cause a “humanitarian catastrophe.”

“Our goal is to alleviate the concerns of our Russian counterparts and get rid of the terrorists in that area,” he told a briefing in Moscow. “We can work together but we could be putting civilian lives at risk while eradicating those radical groups.”

Russia, which has been a key backer of Al Assad, launched its operation in Syria in 2015, ultimately helping to turn the tide of the war in Al Assad’s favour.

Turkey, which supports some of the opposition groups along its border with Syria, has mediated ceasefire deals in several areas in Syria, including Idlib. Russia and Iran, who back Al Assad, have also mediated ceasefires of their own. In most such cases, opposition groups on the verge of surrender gave up their fight and were evacuated to remaining areas outside regime control, namely Idlib.

Taking Idlib by force would be a difficult challenge for Al Assad’s forces. As talk of a new regime offensive swirled earlier this week, the leader of Syria’s Al Qaida affiliate that is based in the province, vowed to fight on there. Abu Mohammad Al Golani said on Wednesday that state-sponsored surrenders of rebel groups won’t happen in Idlib like they did elsewhere, because they would be considered “treason” by his Al Qaida-linked fighters.

Russia’s Lavrov on Friday indicated that Moscow was losing patience with the Idlib militants, whom the Kremlin has accused of targeting regime positions as well as Russia’s Syria military base from there.

Lavrov acknowledged that the situation in Idlib is “complex” and called for the separation of militants from legitimate opposition groups. He said Cavusoglu will stay on in Moscow to join a meeting later on Friday with top Russian and Turkish defence and intelligence officials to discuss the situation in Idlib.