The first troops of a main contingent of Japanese forces arrived in Kuwait on Wednesday on their way to start a humanitarian mission in southern Iraq.
The deployment - the first of Japanese troops to a war zone since World War Two - has been condemned by critics at home as a violation of the country's pacifist constitution.
Team commander Colonel Yasushi Kiyota told reporters some 90 members of the Ground self-defence Force, which arrived at Mubarak Air Base near Kuwait City early Wednesday, will be leaving for Iraq within a few days.
The unit members dressed in commando fatigues and green berets include engineers and security personnel who will help build a camp on the outskirts of the southern Iraqi city of Samawa, where the mission will be deployed.
"We, the Japanese Ground self-defence Forces, are here to assist the reconstruction of Iraq," Kiyota said. "We've done a lot of different kinds of training and through this we are confident that we can arrive in Samawa safely."
The group later arrived at Camp Virginia in northern Kuwait. Before leaving for Iraq, they will train at the transit camp for US forces and troops from other nations helping to police Iraq after the US-led war which ousted Saddam Hussein last year.
Nudged by its key ally, the United States, to take a bigger global security role, Japan plans to deploy around 1,000 military personnel to the region to help rebuild Iraq.
An advance team of ground troops arrived in Samawa last month while an air force team comprising about 200 personnel who will fly humanitarian supplies to Iraqi cities has landed in Kuwait in three tranches in December and January.
The rest of the main contingent of nearly 600 soldiers is due to leave Japan in three waves beginning later in February.
US forces spokesman Captain Randall Baucom told Reuters it was under discussion whether the Japanese would conduct live ammunition drills.
The deployment has divided public opinion in Japan and Prime Minister Junichiro Koizumi's government could face the country's first military casualties since World War Two.
Japanese troops have been on peacekeeping missions but haven't fired in combat since 1945.