Turkey will not allow "terror to take root" or "fait accompli situations" next to its borders, President Tayyip Erdogan said on Thursday, a day after Russia launched air strikes in neighbouring Syria.
Russia launched its biggest intervention in the Middle East in decades on Wednesday, targeting areas near the cities of Homs and Hama in the west of the country, where President Bashar al-Assad's forces are fighting a number of insurgent groups, though not Islamic State, which is based mostly in the north and east.
The move by Moscow puts Ankara - which has long called for Assad's removal - in an uncomfortable position, raising questions about its ability to contain the fallout from a worsening military and humanitarian crisis on its doorstep.
"Turkey will not allow terror to take root or one-sided 'fait accompli' situations right next to her borders," Erdogan said in a speech in parliament.
Russian jets launched a second day of strikes in Syria on Thursday, targeting areas held by an insurgent alliance that includes a group linked to al Qaeda, but not the Islamic State militants Moscow earlier said it had hit.
An opposition Turkmen group said some of Wednesday's Russian strikes had hit Free Syrian Army sites and killed dozens of civilians.
Russian President Vladimir Putin said on Thursday that assertions that civilians had been killed in Russian air strikes in Syria were an "information attack".