A US service member was killed in northern Iraq on Saturday, a Pentagon spokesman told AFP, with US media reporting it came after a rocket attack on a base.

The US-led coalition against the Islamic State group earlier said that a service member had been killed due to enemy action, but had declined to specify the nationality of the dead.

The last US service member to be killed in Iraq as a result of hostile enemy action was Army soldier Master Sgt. Joshua Wheeler, who died in October during a rescue mission, also in northern Iraq, CNN and other media said.

The latest fatality came after an indirect fire rocket attack on a base at Makhmur, CNN said, citing a US official and saying that a "small number" of other American troops were wounded in the attack.

It was not exactly clear how many and the Pentagon spokesman declined to give further details.