U.S. Defense Secretary Ash Carter called on Turkey to "stay focused" on the fight against the Islamic State and not to fight Syrian Kurdish forces backed by the United States.
"We do understand that [Turkey and Kurdish fighters] have historical differences with one another, but American interests are quite clear," Carter said. "We, like they, want to combat ISIL and we are calling on them now: 'Let's keep our priorities clear here'."
Carter's remarks on August 29 followed a Pentagon statement earlier in the day saying that clashes between Turkish and U.S.-backed Kurdish forces south of the Euphrates River town of Jarablus were "unacceptable" and of "deep concern."
Carter told Pentagon reporters that Joint Chiefs of Staff Chairman General Joseph Dunford spoke to his Turkish counterpart on August 28. Carter said he intends to discuss the Kurdish matter next week in Europe with Turkish defense minister Fikri Isik.
Despite the U.S. rebukes, Turkish President Recep Tayyip Erdogan said on August 29 that Turkey will press ahead with its military operation in Syria until IS and the Kurdish Syrian fighters -- who he calls "terrorists -- “cease to be threats for our citizens."
Based on reporting by AP and Reuters