The first troops of a main contingent of Japanese forces have entered Iraq from Kuwait in Japan's most controversial and risky deployment since World War Two.
Some 80 members of the Ground Self-Defence Force crossed the border into southern Iraq early on Sunday morning in a convoy of trucks and armoured vehicles emblazoned with Japanese flags.
The unit - part of a contingent of 600 soldiers - will first set up a camp on the outskirts of the southern Iraqi city of Samawa, where the mission will be deployed.
There is much concern in Japan about the safety of Japanese military personnel who are being sent to help rebuild Iraq after the U.S.-led war which ousted Saddam Hussein last year.
"I am very tense because this is a serious mission," Major Itaru Murakami, dressed in camouflage fatigues, flak jacket and helmet, told Reuters at the border. "But we are well-prepared."
The deployment is expected to involve up to 1,000 army, air force and navy personnel in Iraq and nearby countries. It could have serious political consequences for Prime Minister Junichiro Koizumi if there are casualties.
Japanese troops have not fired a shot in combat since 1945 and the Iraq mission has been criticised by some in Japan as a violation of the country's pacifist constitution.
The dispatch was made possible by a law passed in July, which in line with the constitution limits military activity to "non-combat zones", a murky concept in Iraq, where there are almost daily attacks on U.S. forces and their allies.
"I'm excited because this is the first mission for Japan in a long time," said Master Sergeant Toshio Abe. "We are going to Iraq on a humanitarian mission, to help the people, to help in reconstruction."
An advance team of ground troops arrived in Samawa last month. The rest of the main contingent is expected to depart Japan starting later in February. A 200-strong air force team to airlift supplies to Iraq is now in Kuwait.