TOKYO - The top US allies in Asia, Japan and South Korea, offered early support Thursday for President Bush's announcement of a boost in American troops in Iraq.

Japanese Prime Minister Shinzo Abe, whose government is providing humanitarian air assistance in Iraq, offered his support in a telephone conversation with Bush from Berlin.

"Japan regards highly President Bush's strong resolve toward Iraq's stability," Chief Cabinet Secretary Yasuhisa Shiozaki told reporters in Tokyo.

Japan withdrew its 600 non-combat ground troops from southern Iraq last year, but has continued air support and Abe has made firm support for Bush a cornerstone of his foreign policy since taking office in September.

South Korean President Roh Moo-hyun also conferred with the American president by telephone ahead of the announcement and expressed support for the new policy, Roh's office said.

Bush called the two leaders to explain his new policy on Iraq before his speech to the American people, in which he announced a deployment of 21,500 additional US forces to Iraq and acknowledging failures in past policy.

The South Korean president "said he understood the background of the comprehensive US policies and expressed support for President Bush's endeavor to bring about stability and reconstruction in Iraq," Roh's office said.

South Korea has 2,300 troops in the northern Iraqi city of Irbil to support the US-led reconstruction of Iraq. Seoul's current contribution of forces makes it Washington's biggest coalition partner after Britain.

Seoul plans to withdraw 1,100 troops by April, and parliament has instructed the administration to devise a full pullout plan during 2007.