More than 2,200 U.S. Marines based in Okinawa Prefecture and an amphibious assault ship homeported in Nagasaki Prefecture are heading to the Middle East, as the United States and Israel’s war against Iran enters its third week, media reports said Friday.

The U.S. military is sending the roughly 2,200-strong 31st Marine Expeditionary Unit and USS Tripoli amphibious assault ship, homeported in Sasebo in Nagasaki Prefecture, to the region as Iran ramps up attacks in the Strait of Hormuz, a crucial artery for oil shipping.

The Tripoli, which carries a squadron of F-35 fighters, V-22 Ospreys and helicopters, is the command ship of a Marine Amphibious Ready Group, which includes two other vessels. It was not immediately clear if the two other ships would also be heading to the Middle East.