Unlike most other heads of state, with the occasional exception of the British monarch and the president of Russia, the U.S. president is accompanied on all foreign and domestic trips by a full motorcade of U.S. government vehicles, including several presidential limousines, escort vehicles and a military ambulance, all of which are transported by the United States Air Force using C-17 Globemaster III aircraft. For security reasons, the president always travels in "the Beast" on trips abroad. The U.S. vehicles are typically complemented with coaches, police vehicles, ambulances and limousines provided by local authorities. The United States Secret Service also has a fleet of heavily armored buses called Ground Force One for the president and presidential nominees.