ANKARA — Turkey will not take the "smallest step back" in Syria's last rebel bastion of Idlib, where several of its army posts have been surrounded, President Recep Tayyip Erdogan said on Wednesday.

"We will not take a smallest step back in Idlib, we will certainly push the regime outside the borders we designated, and ensure the return of the people to their homes," Erdogan told his ruling party's lawmakers in parliament in Ankara.

As part of deals with Russia — a key supporter of President Bashar Al-Assad — rebel backer Turkey has 12 observation posts in Idlib but several of them have come under fire from Assad forces this month.

Ankara has confirmed as many as 17 Turkish security personnel have been killed, which prompted officials to turn to Russia.

Erdogan repeated his call for Damascus to "stop its attacks as soon as possible" and pull back from Ankara's army outposts by the end of February.

"The time we have given to those who besieged our observation towers is running out," Erdogan said.

"We are planning to save those of our observation posts from the besiegers one way or another by the end of this month."

Erdogan added: "The biggest problem we have is that we cannot use the air space" over Idlib which is controlled by Russia.

"Hopefully, we will find a solution soon," he said.

In recent weeks, Damascus backed by Russian airstrikes has pressed a major offensive against the remaining territory still held by jihadists and Turkish-backed rebels.

The area hosts more than three million people — half of them already displaced by violence elsewhere.

The offensive has killed more than 400 civilians, according to the Syrian Observatory for Human Rights, and displaced close to a million people amid bitter cold. — AFP