The "Angkor Sentinel 2011" multinational peacekeeping military exercise kicked off Monday at Cambodia's military commanding headquarters in Kampong Speu province, some 50 kilometers west of Phnom Penh, a senior military official said Monday.

The exercise, co-hosted by the United States, involves 300 members of the Cambodian armed forces, 200 ones of the U.S. Army Pacific, and some others from Mongolia, Indonesia and Nepal, said Lt. Gen. Chhum Socheat, the spokesman for Cambodian Defense Ministry.

"It's to strengthen and expand cooperation between Cambodia and the United States in peacekeeping operations and humanitarian activities," he said.

The 12-day training (May 16-27) focuses on command post exercise, engineering work such as building school and hospital, humanitarian affairs, rescues and medical treatment, he said.

"Angkor Sentinel 2011" is a part of the Global Peace Operations Initiative (GPOI) program, the United Nations Peacekeeping framework for strengthening peace and security.