Japan has deployed about 600 troops to the southern Iraqi city of Samawah since early 2004 in Tokyo's largest military mission since the end of World War II. The strictly non-combat troops are limited to purifying water and other aid tasks.

Prime Minister Junichiro Koizumi, a vocal supporter of the U.S.-led invasion of Iraq, said the deployment was needed to help rebuild the country and ensure that terrorists do not block the road to peace.

"We decided that we need to support the effort of the Iraqi people to establish a stable and democratic government," Koizumi told reporters after the extension was approved. "So we decided to extend our mission there."

Koizumi, who is coming under mounting domestic pressure to schedule a withdrawal of troops as security deteriorates in Iraq, said he was undecided about when the Japanese soldiers would come home. But he insisted it was too soon yet to pull out.

"Withdrawing from Iraq now would mean a surrender to terrorist efforts," he said. "We should not allow Iraq to become a hotbed of terrorism."

The extension allows Japanese troops to stay in Iraq until Dec. 14, 2006, but the government is still free to withdraw them before that date. Japanese press reports have speculated a withdrawal could come in mid-2006.

The mission has never been popular in Japan, facing criticism that it violates the country's pacifist constitution. Many fear the deployment has made the troops and Japan itself a target for terrorists, or that the troops will get drawn into the fighting.

That opposition has grown in recent months. The Japanese camp in Samawah has suffered sporadic attacks, but no Japanese soldier has been hurt. Rock-throwing demonstrators near Samawah over the weekend demanded a Japanese withdrawal.

In Hiroshima, Mayor Tadatoshi Akiba called the extension "truly regrettable" and said, "The public opinion is increasingly opposing the extension and many other countries are withdrawing. The issue was never fully discussed by the Parliament and the decision lacks public consensus."

About 90 members of the Japan Congress Against A- and H-Bombs held a sit-in protest in the city's peace memorial park, protesting the extension, said member Kazutoshi Kajikawa.

Speculation has been running high in Japan that Tokyo will pull its troops out as the British and Australian soldiers protecting them also withdraw, but that has not been confirmed by Japanese officials.

Takenori Kanzaki, head of ruling partner New Komeito Party, said, "I assume a withdrawal would begin around March, but a decision will be made by the government after thorough consideration."

Koizumi, however, urged Iraqi authorities to improve security in the country so that such military missions are no longer required.

"I hope there will be a situation as soon as possible in which the Iraqi people can continue their own efforts for reconstruction without relying on other countries' support," he said.

On Thursday, Japan also decided to provide US$14.4 million (euro10.9 million) in new aid to Iraq to help create jobs and improve electricity supply in southern Iraq, a Foreign Ministry statement said.

Iraqi Prime Minister Ibrahim al-Jaafari visited Japan this week and urged Koizumi to extend the mission. Defense Agency chief Fukushiro Nukaga made a rare trip to Iraq over the weekend to survey the troops, and declared Samawah to be relatively safe. The visit was apparently aimed at calming Japanese nerves ahead of the dispatch extension.

Questions about the effectiveness of the deployment have also come up. With the government eager to avoid any incident, Japanese troops have been largely confined to the safety of their base, limiting their humanitarian duties.

The deployment has been a cornerstone of Koizumi's efforts to bolster Japan's international diplomatic role and loosen controls on the military so that it can join more peacekeeping missions and cooperate more actively with the United States.

Japan provided maritime logistical support for the U.S.-led invasion of Afghanistan. That mission was extended by parliament in October. Japanese cargo planes are also flying support missions in the Middle East.

In tandem with the deployments, the government has been campaigning hard to win a permanent seat on the U.N. Security Council, has ramped up military cooperation with the United States, and is pushing to make the Defense Agency into a full-fledged ministry.

Japanese military action is strictly limited under the country's U.S.-drafted 1947 constitution, which bans Japan from offensive military action. Koizumi's government is working on a revision of the charter to loosen those controls.

Sound Off...What do you think? Join the discussion.

Copyright 2012 Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.

More Military Headlines

• Socom Refines AC-130J Gunship Plans
• TV: Women Fare Badly in Super Bowl Ads
• Iraq, Afghan Refugees Start Over in US
• Pentagon Seeks More Power From Vehicles
• Underway at Last!