Dec. 9 (Bloomberg) -- Japan said it will begin sending as many as 600 troops to Iraq as soon as Monday, its first overseas deployment outside the United Nations umbrella since World War II ended, to deliver aid and help rebuild roads and hospitals.

Japan will send the troops, as many as four naval vessels and eight transport aircraft to the Middle East nation for as long as a year, the government said in a release. Japanese vehicles and planes will be used only to move humanitarian aid supplies.

Prime Minister Junichiro Koizumi's decision to send troops to Iraq follows the killing of two Japanese diplomats there last month, which stoked public opposition to the deployment. The dispatch may mark a victory for politicians seeking to give Japan's military a freer hand by undermining a constitutional ban on fighting overseas.

``To some it's a clear violation of the Constitution,'' said Shigenori Okazaki a senior political analyst UBS Warburg (Japan) Ltd. ``It's a big gamble.''

Some 34 percent of 1,037 respondents to a telephone survey by Kyodo News Service last week said they oppose the deployment, while 56 percent said Japan needs to be cautious. Sending the troops as soon as possible was supported by only 7.5 percent of those surveyed.

To Help, Not Fight

Japan's forces are going to Iraq to help aid the country, not to fight a war, Koizumi said at a press briefing. While troops will be armed for protection they won't engage in combat and the deployment won't violate Article 9 of Japan's Constitution renouncing the right to wage war, he said.

Japan's decision to send troops to Iraq comes after the world's second-biggest economy in October pledged $1.5 billion in grants next fiscal year to help rebuild that country, which is the world's second-largest holder of oil reserves. Japan promised a further $3.5 billion in low-interest loans in the years to 2007.

The U.S., which is fighting insurgent groups in Iraq, wants Japan's help to widen the number of countries participating in the coalition's effort to rebuild roads, bridges, other infrastructure in the Middle East nation.

``Maintaining our alliance with the U.S. is critical,'' Koizumi said. The exact timing of the first troop dispatches will be decided after consulting military officials, he said.

Howard Baker, the U.S. ambassador to Japan, last week said the deployment of Japanese troops in Iraq would have an ``enormous symbolic effect.''

No Offense

Japan's pacifist constitution bars its military from buying long-range bombers, aircraft carriers or other weapons judged to be offensive. This means the country relies on the U.S. to defend it and to maintain its security in Asia.

Japan spends a 10th of its defense budget -- about 5 trillion yen ($46.6 billion) this year -- on maintaining bases that house about 40,000 U.S. military personnel.

Those include the U.S. Seventh Fleet's home port at Yokosuka, south of Tokyo and U.S. Air Force, Army and Marine Corps units throughout the country, mostly on the southern island of Okinawa, which has the largest concentration of U.S. forces in Asia.

The two countries are preparing to strengthen those ties from next year, when Japan starts preparing to deploy from 2005 a U.S.- built land- and sea-based anti-ballistic missile system to guard against possible attack from North Korea or other nations.

Japan, which is in range of some North Korean ballistic missiles, is relying on the U.S. along with South Korea, China and Russia to help persuade North Korea to halt any bid to develop nuclear weapons.

Opposition

Opposition lawmakers in Japan oppose the deployment to Iraq, saying the risk to Japanese troops there will be too great.

``The decision to send troops to Iraq is based on a fundamental miscalculation,'' said Naoto Kan, leader of the Democratic Party of Japan, the largest opposition force in the country's parliament, after meeting with Koizumi today.

The DPJ won 177 seats last month in national elections for the 480-seat lower house of parliament, 40 more than they previously held. The Liberal Democratic Party-led ruling coalition lost eight seats, shrinking its majority to 278. The two parties will face each other again next year in nationwide elections for the 247-seat upper house due by July.

Last Updated: December 9, 2003 05:10 EST