A top general hinted Thursday that American troops will de deployed in Afganistan on a near-permanent basis, and said the United States faces a “protracted, protracted fight” against terrorist groups such as the Islamic State.

“I don’t know if it’s a ‘forever war;’ define forever,” Army Gen. Joseph Votel, who leads the United States Central Command, said during a Q&A at the Aspen Institute. “I think we have to be committed to this. I think this is a protracted conflict against these organizations. A successful operation in Mosul won’t eliminate ISIL. They will go to the next version of ISIL. They will adapt and we will have to adapt.”