About 22,000 military and coast guard personnel from seven countries will take part in Rimpac 2000, a series of military drills in waters off Hawaii that start Tuesday and continue for about a month.
Six countries on the Pacific Rim plus Britain are participating this year, the most ever. The six are Japan, the United States, Australia, Canada, Chile and South Korea.
More than 50 ships and 200 aircraft will participate in the joint exercises, the largest of their kind in the Pacific region.
The Maritime Self-Defense Force is dispatching about 2,000 personnel, eight warships, a supply ship, submarines and P-3C antisubmarine aircraft.
During the last exercises in 1998, budget constraints forced the MSDF to reduce its contribution by about one-third of usual levels.
Rimpac 2000 will be the first time Japan has participated since introducing last summer a new set of mutual defense guidelines aimed at expanding Japan's military ties with the U.S.
Since the end of the Cold War, the exercises have shifted their focus to peacetime naval operations and dealing with regional disputes.
This year's drills will incorporate sea and air counterstrikes and antisubmarine warfare. Exercises for humanitarian assistance to refugees will also be carried out.
This year's Rimpac exercises will be the 17th since they began in 1971. They are held every two years.