Turkey says Washington has pledged to stop giving arms to YPG Kurdish forces in Syria, as Ankara's Olive Branch offensive against US-backed Kurdish militia there enters its second week.
On Friday, Erdogan repeated his intention to expand the military operation against Kurds in Syria, targeting fighters he says are linked to a Kurdish terror group.
Turkish forces are set to push the operation to the city of Manbij and then as far east as the Iraqi border.
The move could pit Turkish forces against some of the 2,000 U.S. troops that are in Syria as part of an international coalition to eliminate the Islamic State militant movement in Syria.
The Turkish incursion in northwest Syria's Afrin region has opened a new front in the multi-sided Syrian civil war, but has also further strained ties with NATO ally Washington.