"Mr Erdogan declared Turkey's priority is to maintain peace on its borders" as well as "the unity, stability and territorial integrity of Syria," where last week a Islamist-led rebel coalition went on the offensive, breaking a years-long stalemate in Syria's civil war.

Erdogan's office said he had "urged the Syrian regime to engage in a real political process to avoid the situation deteriorating."

Turkey's head of state also warned "he had taken and would take measures to prevent the terrorist organisation PKK (Kurdistan Workers' Party) and its extensions from taking advantage of developments" in northern Syria, home to numerous Kurdish fighters.

Islamist group Hayat Tahrir al-Sham and other rebel groups have seized a large swathe of the northern city of Aleppo in recent days, and are now advancing towards the central city of Hama.

Iraq, which has assured Damascus of its support, sent armoured vehicles Monday to bolster security on its 600-kilometre (375 miles) long border with Syria.

The resumption of hostilities in Syria's civil war has intensified diplomatic manoeuvres in the region.

Iranian Foreign Minister Abbas Araghchi notably held talks in Ankara on Monday with his Turkish counterpart Hakan Fidan, a day after visiting Damascus, where he met President Bashar al-Assad in Damascus.

Tehran was a staunch ally of Assad during the civil war that broke out in 2011.