The first Japanese troops deployed to a combat zone since World War II marked the end of their mission Saturday by celebrating the return of the army flag that flew over them for 2 1/2 years in Iraq.

About 500 troops who recently returned from the humanitarian mission in a sparsely populated part of southern Iraq attended the ceremony at the Ground Self-Defense Forces Asaka training grounds just north of Tokyo.

CountryWatch:Japan

Prime Minister Junichiro Koizumi, Foreign Minister Taro Aso, Defense chief Fukushiro Nukaga and Iraqi ambassador to Japan Ghanim Alwan al-Jumaily were also present, along with supporting troops and about a thousand well wishers.

"The troops did an admirable job in the most difficult of conditions," Koizumi told the crowd. "This mission will remain in the memories of both the Japanese and Iraqi people."

The mission to the southern city of Samawah boosted Japan's international profile and strengthened its ties with the United States — Japan's biggest ally — but also tested the limits of the country's pacifist constitution and was widely criticized at home.

The troops were dispatched to Iraq under a special law and their activities greatly limited. They were heavily dependent on Dutch, Australian and British forces for security, and suffered no combat-related casualties.

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.

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. Aso said earlier this month that Japan is open to sending peacekeeping troops back to Iraq, but only if the security situation improves there.

The ruling Liberal Democratic Party has also proposed revising the constitution to delete phrasing that renounces the country's right to wage war.