Prime Minister Junichiro Koizumi's (searchCabinet on Tuesday approved the dispatch of about 1,000 soldiers to help in the reconstruction of Iraq, the biggest deployment of Japanese troops (searchoverseas since World War II (search).

In a special meeting, the Cabinet approved the dispatch of troops to southeastern Iraq to restore water services, offer medical and other humanitarian assistance and help rebuild schools and other infrastructure.

The dispatch, expected to begin over the next month, will involve elements of Japan's land, sea and air forces.

Following the Cabinet meeting, Koizumi went before the nation to explain why he is pushing ahead with the controversial plan, which opposition leaders say could draw the troops into combat and violate Japan's postwar pacifist constitution.

"We are not going to war," Koizumi said. "The situation in Iraq is severe. We know it is not necessarily safe. But our Self-Defense Forces must still fulfill this mission."

Koizumi has repeatedly vowed to dispatch the troops as soon as the situation in the region is secure enough. But, facing intense political pressures and a skeptical public, he has refrained from setting a specific date.

The outline announced Tuesday left the timing of the dispatch open, though a small advance contingent expected to leave before the end of the year. Japan's defense minister was expected to set the date by early next week.

Under the plan, 600 ground troops will be sent, along with armored vehicles and up to six naval ships, including destroyers. Eight aircraft, including three C130 transport planes, will also be deployed.

The total number of troops would be about 1,000, making it the largest overseas deployment since World War II, according to the Defense Agency.

The troops will stay for six months to one year, and, as defensive measures, carry rocket-propelled grenade launchers and other arms that Japanese peacekeepers have never used, reports in most major newspapers said, quoting unnamed ruling party sources.

Koizumi stressed the need for Tokyo to live up to its international responsibilities, and its commitments to the United States, Japan's most important ally and trading partner. Japan was criticized by Washington for contributing only money, and not personnel, during the first Gulf War in the early 1990s.

"America has made many sacrifices to create a viable democracy in Iraq," he said. "Japan must be a trustworthy ally for the United States."

The deployment would be a milestone for Japan's military, which is strictly limited by the constitution.

A special law allowing the dispatch for humanitarian missions in Iraq was passed by Parliament in July, but only under the condition that the troops be sent to a place deemed safe and away from combat.

Opponents of the dispatch say Iraq is still not secure enough to fulfill that requirement, and argue that the troops could be drawn into fighting to protect themselves.

Such dangers were underscored last weekend, when two diplomats were gunned down near the northern Iraqi city of Tikrit. They were Japan's first casualties since the U.S.-led war in Iraq began in March.

No Japanese soldier has been killed in combat since World War II.

Officials have stressed that the area of Iraq where the troops are to go is less dangerous than Tikrit.

Opposition leaders have vowed to derail Koizumi's plan.

Most Japanese lean toward the opposition. Polls indicate only about a third of the voters support Koizumi's plan.

Japan sent 600 troops to Cambodia on a peacekeeping mission in 1992, and 405 on a separate, ongoing mission to East Timor.