Defense Secretary Ash Carter applauded U.S.-backed coalition forces for opening a new “isolation” effort in Raqqa on Sunday as part of an operation to remove the Islamic State from its de facto capital in Syria, but neglected to offer any hint of progress made with Turkey in negotiating allowing the Kurdish-led Syrian forces to enter the city.

“I welcome today’s announcement by the SDF that the operation to free Raqqa from ISIL’s barbaric grip has begun,” Carter said in a statement, referring to the Syria Democratic Forces — a coalition of Kurdish, Arab and Christian forces.