Turkey has been opposed to the Syrian government’s crackdown on the rebels and has sought to remove Mr. Assad from power. It is also engaged in the fight against Islamic State militants in Syria. Mr. Erdogan first sent ground forces, backed by American air power, into Syria last month to fight the Islamic State. They have sought to roll back the territorial gains of Kurdish militants, who are also fighting the Islamic State. Turkey considers the Kurdish militias in Syria a threat, saying they are allied with Kurdish insurgents in Turkey.

On Tuesday, Mr. Erdogan also renewed his request for a no-fly zone over the border area between Turkey and Syria. He has long pushed to establish a safe zone across the border to accommodate Syrian refugees and help curb the flow of migrants through Turkey and on to Europe.

Turkish officials have vowed to continue military operations in the border region with Syria until all threats to its national security are removed. Turkey is also reeling from a failed coup in July that aimed to topple the government of Mr. Erdogan and left at least 240 people dead.

On Tuesday, Mr. Erdogan called on world leaders to take measures against the organization of Fethullah Gulen, a Muslim cleric living in self-imposed exile in the United States whom Mr. Erdogan has accused of orchestrating the coup. Mr. Gulen has denied involvement.