Turkish Foreign Minister Mevlut Cavusoglu on Friday said US President Donald Trump told his Turkish counterpart that the United States will no longer supply arms to People's Protection Units (YPG) Syrian Kurdish fighters.
Cavusoglu said on Friday that Trump relayed his decision during a telephone conversation with Turkish President Recep Erdogan.
Cavusoglu said he was present in Erdogan's office during the telephone call.
Turkey considers the YPG to be terrorists because of their affiliation to outlawed Kurdish rebels that have waged a three-decade-long insurgency in Turkey.
The YPG was a key US ally against ISIS in Syria.
There was no immediate reaction from the United States.
But Turkey's announcement appeared to catch the Pentagon and the US State Department off-guard.
Officials at both agencies, who would normally be informed of changes in US policy toward arming the Syrian Kurds, said they were unaware of any changes.
The officials spoke on condition of anonymity.