US assures Turkey over arming Kurds in IS fight

"We are being transparent with Turkey on the details on what we are providing," said Baghdad-based Pentagon spokesman Colonel Ryan Dillon.

"We are maintaining full accountability of the weapons we are providing the SDF," he said, referring to the Syrian Democratic Forces, a Kurdish-Syrian Arab alliance now moving in on the Islamic State group's Syria stronghold of Raqqa.

The SDF includes fighters from the Kurdish Peoples' Protection Units (YPG), which Turkey links to Kurdistan Workers' Party (PKK) separatists it calls a terror group.

In May, US President Donald Trump approved arming the YPG to support the assault on Raqqa.

Turkey on Tuesday said arming the YPG was an "extremely dangerous" move and urged Washington to reverse its "mistake."

The arms going to the SDF could include anti-armour weapons like rocket-propelled grenades or TOW missiles, in addition to vehicles, AK-47s and small-calibre machine guns.

Dillon said any arms provided will be recorded by serial number.

"We will maintain that in our database, and we will share that information with allies to the north that are concerned about the weapons we are providing," he said.