SEOUL, June 29 (Xinhua) -- U.S. Forces Korea (USFK) moved its headquarters Friday to a new garrison south of the capital Seoul in a relocation project, to which South Korea and the United States agreed in May 2003.

The USFK held a ceremony to open the new headquarters at Camp Humphreys in Pyeongtaek, about 70 km south of Seoul. The USFK headquarters was moved from Yongsan in central Seoul.

The opening ceremony was attended by some 300 military and government officials of the two countries, including USFK commander Gen. Vince Brooks, South Korean Defense Minister Song Young-moo and Lee Sang-chul, deputy director of the National Security Office (NSO) of the presidential Blue House.

South Korean President Moon Jae-in said in a speech, read out by the NSO deputy director, that he anticipated the South Korea-U.S. alliance evolving into a great alliance beyond the military, comprehensive one through the opening of the Pyeongtaek era.

The new USFK headquarters consists of a four-story main building and a two-story annex, spanning 24,000 square meters.

Seoul and Washington agreed in May 2003 to the relocation program to consolidate U.S. bases across South Korea into two garrisons in Pyeongtaek and Daegu, a city in North Gyeongsang province.

The construction work took about 10 years. More than 90 percent of the 10.8 billion-U.S.-dollar project was funded by the South Korean government.

U.S. troops stationed north of Seoul began moving to Pyeongtaek in 2013. The Eighth U.S. Army, a key USFK ground component, relocated its headquarters to Pyeongtaek in July last year.

The South Korea-U.S. Combined Forces Command (CFC) was planned to move to a separate seven-story building inside the South Korean Defense Ministry's headquarters in Seoul by the end of this year.

The Pyeongtaek U.S. garrison, spanning 14.677 million square meters, is the single biggest U.S. base abroad.