The last batch of Japanese troops touched down on Japanese soil Tuesday, wrapping up the country's humanitarian mission inside Iraq, its biggest and most dangerous overseas deployment since World War II.

About 280 soldiers from the Ground Self-Defense Force arrived at Tokyo's Haneda airport by plane from Kuwait, Defense Agency spokesman Hirokazu Shirota said. They were the last of three flights bringing all the Japanese troops back.

CountryWatch: Iraq

The arrival ends 2 1/2 years of noncombat, humanitarian work in the southern Iraqi city of Samawah in support of the U.S.-led coalition. The mission helped raise Japan's international profile and strengthen ties with its biggest ally, the United States, but also tested the limits of the country's pacifist constitution and was wildly criticized at home.

The first group of troops returned last Thursday, the second on Sunday.

Security duties in the southern province where they were posted will be transferred from the U.S.-led coalition to Iraqi forces.

Tokyo is not completely withdrawing from the Iraqi region. Government officials have said Japan plans to expand its Kuwait-based air operations to ferry U.N. and coalition personnel and supplies to Iraq.

Tokyo dispatched its troops in 2004 — the country's largest military deployment and first to a combat zone since World War II — under a special law because the country's pacifist constitution bans it from taking part in warfare.

A total of 5,500 troops were deployed to Iraq in groups of up to 600, Kyodo News agency has reported.

The troops' activities in Iraq were greatly limited, however. Assigned to a sparsely populated part of southern Iraq, the troops were heavily dependent on Dutch, Australian and British forces for security, and suffered no combat-related casualties.

Earlier this month, Foreign Minister Taro Aso said Japan is open to sending peacekeeping troops back to Iraq, but only if the security situation improves there.

Prime Minister Junichiro Koizumi, a strong backer of U.S. operations in both Afghanistan and Iraq, has clearly stated he hopes the Samawah mission will lead to more overseas deployments. The ruling Liberal Democratic Party has also proposed revising the pacifist constitution to delete phrasing that renounces the country's right to belligerency.