Wearing dark suits and ties, more than 30 Japanese soldiers arrived in Kuwait on Saturday to prepare the way for a humanitarian mission in neighboring Iraq, despite controversy over the deployment at home.

Expected to arrive by March, the 1,000-strong Japanese contingent will help purify local water supplies, rebuild schools and provide medical care in the south of the country. They will carry arms for self-protection but their role will be noncombatant.

The soldiers arrived at Kuwait International Airport carrying military duffel bags and were whisked away in buses escorted by the U.S. military. Reporters were only allowed to watch from behind a wrought iron fence.

At Camp Virginia (search), about 50 miles northwest of Kuwait City, they changed from their suits into fatigues and green berets and set up cots in a huge white tent.

Their commander, Col. Masahisa Sato (search), told reporters at the camp that the deployment was a "historic moment" for his country's self-defense army. "As the forward party, we feel an immense responsibility to fulfill our role," Sato said.

As troops with the U.S.-led coalition in Iraq are killed daily, most Japanese oppose the mission, which puts Japan's soldiers in a combat zone for the first time since World War II. Japan's defeat in that war and the atomic bombings of Hiroshima and Nagasaki are considered horrifying reminders of the devastation of war.

Opposition grew after two Japanese diplomats were ambushed and slain in Iraq late November en route to a conference on reconstruction. But Prime Minister Junichiro Koizumi (search) argues that Japan is fulfilling its international commitments.

The U.S. military has hailed the imminent arrival of Japanese humanitarian troops as a "tremendous contribution."

Koizumi also is building momentum for a historic rethinking of the constraints placed on Japan's military by the war-renouncing 1947 constitution, written by the United States. His party is drafting a revision of the document, which has never been amended.

The rest of the Japanese force -- about 600 ground soldiers and 400 sailors and air force personnel -- could go to Kuwait this month and start moving to Iraq by early February.

A small military team already has flown from Tokyo to inspect the area in southern Iraq where the Japanese will be based.