The United States Navy is part of the United States Armed Forces (the military of the USA). It is the largest navy in the world, with the estimated tonnage of its active battle fleet alone exceeding the next 13 navies combined, including 11 U.S. allies or partner nations. It has the highest combined battle fleet tonnage, and the world's largest aircraft carrier fleet, with eleven in service, two new carriers under construction, and five other carriers planned. With 336,978 personnel on active duty and 101,583 in the Ready Reserve, the U.S. Navy is the third largest of the U.S. military service branches in terms of personnel. It has 290 deployable combat vessels and more than 3,700 operational aircraft .