The Yomiuri Shimbun said Japan had begun looking at the withdrawal of the force, which does reconstruction work in the southern city of Samawa, because a new Iraqi government was likely to be formed by the end of the year.

The paper said the planned withdrawal in May next year of the Australian and British troops who are currently in charge of security in Samawa was influencing Japan's plans.

The paper said the government intended to formally extend the deployment of the force by one year when the current mission expires in December.

Japanese Prime Minister Junichiro Koizumi, a close ally of US President George W. Bush, extended the mission last December for another year.

Koizumi said last month he would decide whether to extend the mission again after seeing the outcome of the war-torn country's referendum on a draft constitution in October.

Japan, Australia, Britain and the United States will hold a meeting of foreign affairs and defense experts from Thursday until Monday to discuss the future activity of their troops stationed in Samawah, the Yomiuri said.

Japan has some 600 troops in Samawa on a non-combat, post-war reconstruction mission in its first military deployment since 1945 to a country where there is active fighting.

The troops are barred by Japan's US-imposed pacifist constitution of 1947 from firing their weapons except in self-defense. Australian and British soldiers provide them with protection.