A branch of the U.S. Army National Guard is stationed in Puerto Rico – known as the Puerto Rico Army National Guard – which performs missions equivalent to those of the Army National Guards of the different states of the United States, including ground defense, disaster relief, and control of civil unrest. The local National Guard also incorporates a branch of the U.S. Air National Guard – known as the Puerto Rico Air National Guard – which performs missions equivalent to those of the Air National Guards of each one of the U.S. states.