The Self-Defense Forces will join in the annual Cobra Gold military exercise in Thailand next month, which this year focuses on disaster relief operations, the Defense Agency said Tuesday.

Japan will be taking part in the command post exercise in the northern city of Chiang Mai, which is one of the drills under the Cobra Gold exercise to be conducted May 2 to 13 by the United States and Thailand, according to the agency.

It will be the first time Japan will actively participate in the exercise after joining as an observer in 2001.

The command post exercise will focus on relief operations in light of the Dec. 26 Sumatra earthquake and Indian Ocean tsunami disaster.

According to the Defense Agency, about 25 members from the three SDF branches will take part.

Besides the command post exercise, Cobra Gold consists of field training and humanitarian aid drills.

Singapore first joined the exercise in 2000. It has been conducted by the U.S. and Thailand since 1982.

About 10 other countries from the Asia-Pacific region are expected to participate as observers in the command post exercise, the 24th in a series.

Another 20 countries, including the nations hit by the tsunamis, and those that took part in disaster relief there, have been invited to a workshop in conjunction with the Cobra Gold exercise.