More members of the National Guard and Army Reserve are expected to be called up as the war with Iran progresses, according to defense officials.

A defense official said there are currently roughly 22,000 Army and Air National Guard outside the U.S. supporting operations all around the world and that number has been consistent.

Units were called up to support Operation Epic Fury before it began and members of the Guard who were there already were assigned to support the operation from the region, the official said.

More Guard and Reservists will be mobilized to support the war, the official said.

A significant percentage of the military crews and hardware deployed around the world come from Guard and Reserve units. The six U.S. service members who have been killed in the war were members of the Army Reserve who were all part of a support unit from Iowa.