Turkey lost eight soldiers a day earlier, including five killed after their tank was hit by the Kurdish militia known as the People's Protection Units (YPG), marking the deadliest day for the Turkish troops since they started the so-called Operation Olive Branch along with the rebel Free Syrian Army.

Erdogan said an investigation had been launched into the attack, including trying to determine which countries supplied the weaponry being used by the YPG, considered by Ankara as a terror group.

"We have some estimations," he said. "When it is finalized, we will share it with the whole world."

Ankara has been infuriated with U.S. training and arming of the YPG as a reliable force in the fight against the Islamic State, and threatened to move on militarily against YPG-held Manbij in northern Syria, where U.S. special operation forces are based.