Turkey will not evacuate its military observation post in northern Syria's Idlib, the last rebel stronghold in the region, after a suspected Syrian government attack this month, Turkish Defence Minister Hulusi Akar said.

Turkey's state-run Anadolu news agency has said that Syrian government forces have carried out at least three attacks near a Turkish observation post in the Idlib de-escalation zone, one of 12 posts set up under an agreement between Turkey, Russia and Iran last May.

"Evacuating the observation post in Idlib after the regime's attack is definitely not happening, it won't happen anywhere," Akar told reporters late on Tuesday.

"The Turkish Armed Forces will not retreat from where it is located."

More than 3 million people live in Idlib and surrounding areas, including many who fled government advances in other parts of Syria in recent years.

At least 180,000 people have fled an upsurge in violence in northwest Syria, and government bombings have killed dozens in the past three weeks.

Since last year, the region has been partly shielded in a ceasefire brokered by Russia and Turkey, but much of the recent fighting has hit that buffer zone.

The possibility of an Idlib offensive has drawn warnings of yet another humanitarian catastrophe, with the United Nations warning that up to 2.5 million people could flee toward the Turkish border in such a scenario.

"The regime is doing its best to disrupt the status quo, using barrel bombs, land offensives and air bombings," Akar said, adding that 300,000 people had been displaced due to the conflict in the past month.

Akar said the beginning of a "new tragedy" had been prevented and he had discussed preventing a new wave of migrants into Turkey with Russian Defence Minister Sergei Shoigu.