An American servicemember died in the fighting to retake Mosul from the Islamic State, the Pentagon announced Saturday.

The servicemember died as a result of “wounds sustained in an explosive device blast” outside of Iraq’s second-largest city, a Defense Department bulletin said. Mosul is the last remaining stronghold of the Islamic State in northern Iraq, as a U.S.-led coalition of Iraqi government and Kurdish fighters have been working to expel the terrorist organization from the country.