"Under the new system, the head of the three arms will directly serve the defense chief so that the chief can operate efficiently in a shorter time," said a spokesman for the Defense Agency.

"There is of course no change in the principle of civilian control," he added.

The Japanese government decided to streamline the chain of command faced with growing security concerns. Communist North Korea, which is in a standoff over its nuclear ambitions, in 1998 fired a missile over Japan into the Pacific Ocean.

The new chain of command sets up a 500-member joint staff office, which will also service as a liaison to US forces in Japan.

"As the US force has a similar structure of an integrated chain of command, our new system is good for the two allies' partnership," said the spokesman.

The United States has some 40,000 troops in Japan under a security alliance formed after World War II.

The two countries are negotiating a realignment plan that would pull out 8,000 troops in response to local concerns, although talks have stalled over the cost.

The ruling Liberal Democratic Party has proposed the first-ever revision of the US-imposed 1947 constitution that would state explicitly that Japan has a military, although the country would remain pacifist.

Prime Minister Junichiro Koizumi has also supported giving the Defense Agency the status of a ministry, putting its chief on the cabinet, although he backtracked on the plan after a bid-rigging scandal among agency employees.

Related Links
Japan Defense Agency