Adm. Samuel J. Locklear III will take over Friday as head of the U.S. Pacific Command at Camp Smith from Adm. Robert Willard, who is retiring.

The change of command will be held at 10 a.m. Locklear was most recently commander of U.S. Naval Forces Europe, U.S. Naval Forces Africa and Allied Joint Forces Command in Naples, Italy.

Locklear was the commander of Joint Task Force Odyssey Dawn, established to command U.S. forces supporting the international response to unrest in Libya.

One of six such commands, U.S. Pacific Command encompasses half the Earth’s surface, from the waters off the U.S. West Coast to the western border of India, and from Antarctica to the North Pole, and including key nations such as Japan, North and South Korea, China, India, Indonesia, Thailand and Singapore.

U.S. Pacific Command includes about 325,000 personnel, or about one-fifth of total U.S. military strength. U.S. Pacific Fleet includes six aircraft carrier strike groups, about 180 ships, 1,500 aircraft and 100,000 personnel.

The 36 nations that form the Asia-Pacific region are home to more than half of the world’s population, 3,000 different languages, several of the world’s largest militaries and five nations allied with the U.S. through mutual defense treaties.

On Oct. 19, 2009, when Willard assumed the Pacific duties from Adm. Timothy J. Keating, Defense Secretary Robert M. Gates and Navy Adm. Mike Mullen, chairman of the Joint Chiefs of Staff, presided over the change of command.