The Pentagon says Iraq's air force has gone after the Islamic State group for the first time using F-16 fighter planes bought from the U.S.

Pentagon spokesman Peter Cook commended Iraq for what he called "its successful use of this cutting edge aircraft" in the campaign to degrade and defeat the group. He provided no details on the operation, which he says was announced Sunday by the Iraqi government.

Iraq took delivery of the first four F-16s in July, with more to come. Iraq's air force has been practically non-existent in recent years and heavily dependent on U.S. air power in the struggle against Islamic State.