Turkey yesterday slammed as "unacceptable" a US announcement that Washington would supply arms and military equipment to Kurdish fighters battling IS jihadists in Syria. "The supply of arms to the YPG is unacceptable," deputy PM Nurettin Canikli told A Haber television. "Such a policy will benefit nobody."

"We expect that this mistake is to be rectified," he said, days ahead of a meeting in Washington between President Recep Tayyip Erdogan and US counterpart Donald Trump.

The Kurdish Peoples' Protection Units (YPG) has been seen by Washington as the best ally against jihadists in Syria. But Ankara regards the group as a terror outfit, as it does the Syrian branch of the Kurdistan Workers' Party, who have waged an insurgency since 1984 inside Turkey that has left tens of thousands dead.

Trump on Monday "authorised the Department of Defence to equip Kurdish elements of the Syrian Democratic Forces as necessary to ensure a clear victory over ISIS in Raqa," Pentagon spokeswoman Dana White had said in a statement.

The weapons are being delivered for use by Kurdish fighters ahead of the upcoming offensive to recapture Raqa.