The Turkish air strikes in northern Syria threatened the safety of US military personnel and the escalating situation jeopardized years of progress against ISIS militants, the Pentagon said on Wednesday.

“Recent air strikes in Syria directly threatened the safety of US personnel who are working in Syria with local partners to defeat ISIS and maintain custody of more than 10,000 ISIS detainees,” Pentagon Press Secretary Brig Gen Patrick Ryder stated.

Earlier on Tuesday, Türkiye struck several targets in Syria after President Recep Tayyip Erdogan issued new threats to launch a ground operation "soon" against Kurdish fighters despite calls for de-escalation from Washington and Moscow.

Ankara launched a series of air strikes in Operation Claw-Sword on Sunday -- hitting dozens of Kurdish targets across Iraq and Syria -- and announcing that its military was once again "on top of the terrorists".

The air raids followed a bombing in Istanbul on Sunday that killed six people and wounded 81.

Türkiye blamed the attack on the Kurdistan Workers' Party (PKK), which is blacklisted as a terror group by the European Union and the United States.