Defense Secretary Ash Carter says the U.S. will announce changes to the Syrian training program within hours, saying the U.S. wants to focus efforts on working with capable Kurdish and other forces in Syria.

Carter was speaking at a press conference in London. He says the work the U.S. has done with the Kurds is a good example of an effective approach with a capable, motivated ground combat force. But he didn't give more details.

U.S. officials have previously described an overhaul of the military's failed effort to train thousands of moderate Syrian rebels to fight the Islamic State group. It would focus more on embedding recruits with established Kurdish and Arab units, rather than sending them directly into front-line combat.