Turkey may launch a military operation into Syria's northwestern Idlib province if the situation is not resolved immediately, President Tayyip Erdogan said Friday as attacks by Russia-backed Syrian government forces risked a new wave of refugees.

Syrian President Bashar al-Assad's forces, backed by Russian air power, have since last week rapidly advanced on Idlib. They have taken dozens of towns, including the key city of Maarat al-Numan, upending the last major rebel-held stronghold in Syria's nearly nine-year war.

The recent campaign has also raised tensions between Ankara and Moscow, which back opposing sides in the conflict. Turkey fears a fresh wave of migrants from Idlib and has 12 observation posts in the region, part of a 2018 de-escalation deal that Erdogan says Russia is now violating.