WASHINGTON (AP) — The White House is confirming that the U.S. is suspending nonlethal aid to rebels in northern Syria amid reports that Islamic Front fighters have seized assets from mainstream, Western-backed rebels.

White House spokesman Josh Earnest says the U.S. is concerned about reports that Islamic Front seized bases and warehouses belonging to the Free Syrian Army. He says the U.S. is trying to inventory the status of U.S. equipment and supplies that have been provided to the Free Syrian Army.

Earnest says all further deliveries of nonlethal assistance have been suspended. But he says humanitarian assistance will continue to flow.

Earnest says identifying and helping the moderate elements of Syria's opposition continues to be challenging for the U.S.

Britain has also suspended delivery of nonlethal aid to Syria's opposition.