Dec. 9 (Bloomberg) -- Japan's Prime Minister, Junichiro Koizumi extended the deployment of his nation's 600 troops in Iraq for another year, saying the U.S. needs support from its allies to rebuild the nation.

``The U.S. should not be left by itself in Iraq,'' Koizumi told a press conference in Tokyo. His Cabinet today approved plans to keep soldiers in southern Iraq and maintain a contingent in Kuwait of three c-130 transport aircraft beyond the previous Dec. 14 deadline to withdraw.

The dispatch of Japanese troops to an overseas combat region, the first since 1945, has been unpopular from the start among Japanese voters. Koizumi acknowledged the threat facing the soldiers as violence escalates ahead Iraqi elections planned for January, promising to withdraw the troops if security deteriorates.

The soldiers, based in the Samawah region, have faced at least five mortar attacks near their headquarters. A rocket attack on the Japanese base last month punctured a storage container within the encampment's perimeter without causing injuries.

The Japanese troops are involved in humanitarian efforts under the protection of Dutch forces that will be withdrawn in March. At least one Japanese hostage and two Japanese diplomats have been killed in Iraq, while there are no reported casualties among the Japanese soldiers serving in the country.

The U.S. is raising troop levels to as many as 150,000 in a bid to ensure security for the January elections. In November, 135 U.S. soldiers were killed, the highest monthly casualty rate since President George W. Bush declared an end to major combat operations in May 2003.

The Japanese mission, the first under a Japanese flag since World War II, is limited by the nation's constitution, which bars its soldiers from fighting in overseas conflicts. Its troops, armed with machine guns, anti-tank missiles and armored personnel carriers, are under orders to retreat if attacked.

Of the three Japanese to have been killed since the country dispatched troops to Iraq, the latest casualty was Shosei Koda, a 24-year-old civilian who was killed in October by an insurgent group demanding Japan withdraw its troops.

To contact the reporters on this story: Tim Kelly in Tokyo at tikelly@bloomberg.net.

Last Updated: December 9, 2004 04:35 EST