Syrian rebel fighters are launching a major military operation backed by Turkish forces into a northwestern area of Syria largely controlled by jihadists, Turkish President Tayyip Erdogan said on Saturday.
HTS is not party to a deal brokered by Russia, Turkey and Iran for the safe zone in the province, one of four such "de-escalation" zones across Syria.
"Today there's a serious operation in Idlib and it will continue, because we have to extend a hand to our brothers in Idlib and to our brothers who arrived in Idlib", Erdogan said.
The president later told reporters the operation was led by Free Syrian Army (FSA) rebels and that the Turkish army was not yet operating there.
The operation is led by Turkish-supported Free Syrian Army rebels.
Appearing to confirm this, Erdogan said: "Idlib is a region where we will provide protection in the inside and Russian Federation on the outside".
"We are taking new steps to ensure security in Idlib", he said.
Russia, an ally of Assad, is backing the operation from the air, he said.More news: Children As Young As One Burnt Alive By Day Care Security Guard
More news: OJ Simpson reveals what he plans to do after release
More news: PSG's draw with Montpellier can't be blamed on Neymar's absence
Ousting HTS forces from the area will be needed to allow the arrival of Iranian, Russian and Turkish forces to implement a de-escalation zone.
The joint mission aims to promote an end to conflict in the region, fight al-Qaeda-linked Jabhat Fateh al Sham and Daesh.
The two leaders discussed developments in Iraq and Syria as well as bilateral relations between France and Turkey, and regional issues, the source, who spoke on condition of anonymity due to restrictions on talking to the media, said.
It seems aimed at curbing the Tahrir al-Sham alliance, Syria's strongest jihadist group apart from Islamic State, and at securing Turkey's frontier.
Idlib has strategic importance for all parties involved in Astana deal, and has shown little signs of de-escalation.
Erdogan said that many Syrians had fled to Idlib from Aleppo.
Air raids on insurgent-held towns in that area in recent days were intense, the Syrian Observatory for Human Rights, a Britain-based war monitor, reported. Nevertheless, Russian Foreign Minister Sergei Lavrov said earlier this week that Russia is ready to support armed groups fighting al-Nusra Front in Syria's Idlib de-escalation zone.