Ankara supports a planned operation to drive DAESH out of its Syrian stronghold of Raqqa but the Democratic Union Party's (PYD) armed wing the People's Protection Units (YPG) should not be the ones at the core of it, Defense Minister Fikri Işık told Reuters on Thursday."What Turkey focuses and insists on is that instead of the YPG forces, the operations must be conducted, as the core of the operations, by the local people of the region, instead of the YPG," Işık said in an interview in London."Turkey will not allow YPG forces to extend their territory and gain power by using the DAESH operations as an excuse," he said.Işık also said that YPG terrorists had still not retreated east of the Euphrates as promised after a U.S.-backed operation to take the Syrian town of Manbij from DAESH.He said Turkey, which launched a military incursion into Syria just over two weeks ago, would seek no other objective around Manbij provided the YPG retreated east.Işık was speaking after a meeting in London with U.S. Defense Secretary Ash Carter, who told reporters that the YPG had indeed returned back across the Euphrates.The two men also discussed the importance of local forces being at the center of any Raqqa operation, the Pentagon said in a statement.It also said Carter had assured his Turkish counterpart of continued U.S. support for Turkey's efforts to clear Daesh from its borders.