Prime Minister Junichiro Koizumi said Wednesday that Japan may not pull its noncombat troops from Iraq until after he is scheduled to step down in September.

Japan's decision to withdraw its 600 troops from the southern Iraqi city of Samawah would be based on "a comprehensive evaluation" of the security and political situation in Iraq, and "wouldn't necessarily be during" his term, Koizumi told reporters.

He also said the security situation in Samawah was "relatively stable," although he said other areas in Iraq were struggling with what appeared to organized terrorist attacks.

Japan, Washington's top ally in East Asia, has been a staunch supporter of the U.S.-led invasion of Iraq. It sent troops there in 2004 to purify water and carry out other humanitarian tasks, but speculation is high that the soldiers will soon be withdrawn.

Public opinion polls show most Japanese oppose the mission, which has been criticized as a violation of the constitution. Many say the deployment has made Japan a target for terrorism.