TOKYO, AP – Prime Minister Junichiro Koizumi on Tuesday announced the withdrawal of Japanese ground troops from southern Iraq, moving to end the country’s largest overseas military operation since World War II.

In a nationally televised news conference, Koizumi said the troops had accomplished their non-combat mission, and he pledged to continue aiding Iraqi reconstruction.

He offered no timetable for the withdrawal, but Defense Vhief Fukushiro Nukaga told reporters earlier in the day that the pullout would take “several dozen days.”

Koizumi, who steps down in September, has been a vocal supporter of U.S. policy in Iraq. He is to travel to Washington for a summit with President Bush later this month.

Japan will now consider expanding air operations in Iraq to include transport of medical supplies and U.N. personnel, following a request from U.N. General-Secretary Kofi Annan, said Takenori Kanzaki, head of the ruling party’s coalition partner, the New Komei Party.

“Even after the withdrawal from Iraq, we must continue the efforts to support Iraq,” he told reporters.

Japan has about 600 troops in the city of Samawah in southern Iraq. Dispatched in early 2004, they helped with projects such as rebuilding the infrastructure of the area.

Although the mission was strictly humanitarian, polls show most Japanese were opposed to it, worried the troops would be drawn into the fighting or become targets of terrorists.

Critics also said the dispatch violated the U.S.-drafted 1947 constitution, which foreswears the use of force to settle international disputes. The Iraq mission followed a dispatch of Japanese ships to offer logistical support for military action in Afghanistan.

The pullout was prompted by the announcement on Monday that Britain and Australia would hand over to Iraqi forces the responsibility for security in southern Muthana province, where the Japanese troops are based.

Koizumi defended the deployment on Tuesday.

“I believe we made the right decision,” he said.

While no Japanese soldiers suffered casualties, other citizens in Iraq were targeted by militants demanding a Japanese withdrawal. Seven Japanese have been kidnapped in Iraq since the dispatch, and two of them were killed.

In April 2004, three Japanese aid workers were kidnapped and threatened with death unless Tokyo withdrew. Koizumi refused, and all three were later released unharmed.