The posts were established under a September 2018 deal between Syrian regime ally Moscow and Ankara, which backs the rebels, to avert an all-out Syrian government onslaught in Idlib.

Government forces surrounded one of 12 Turkish observation post in Idlib province on Monday after overrunning nearby areas in a push to take the last opposition holdout, according to the Syrian Observatory for Human Rights.

"We respect the agreement reached with Russia and we expect Russia to abide by this agreement," Turkish Defence Minister Hulusi Akar said in comments published on Sunday on the defence ministry's Twitter account.

"We will by no means empty those 12 observation posts, we will not leave there," Akar said.

His comments came during a visit together with top army commanders to the southern province of Hatay on the Syrian border to inspect Turkish troops on Saturday.

Turkey, worried over a new wave of refugees from the Idlib region, is pressing for a fresh ceasefire deal, as it sent a delegation to Moscow on Monday.

Akar's visit to soldiers on the border region comes as Turkey is also readying to send troops to support the UN-recognised government in Tripoli against strongman Khalifa Haftar's self-styled Libyan National Army.

President Recep Tayyip Erdogan on Thursday said Ankara would respond to an invitation from the Libyan national unity government and Turkish parliament would vote on a motion to send troops as soon as it returns from recess as early as next month.

Ankara signed in November a security and military cooperation deal with the Tripoli-based Government of National Accord (GNA) but in order to send troops, parliament needs to vote a motion like it does for Iraq and Syria.

The official Anadolu news agency, citing sources in Erdogan's ruling party, reported that the timetable could be brought forward and the motion could be presented to parliament speaker's office on Monday.

The General Assembly could vote the measure in an extraordinary session on Thursday, it said.