"(The Self-Defense Forces') international contributions have come to be highly praised both at home and abroad," Koizumi said in a speech at a military parade.

"From now on, to secure our own country's safety and prosperity, it is necessary to positively contribute to the peace and stability of the international community," said Koizumi, a fervent supporter of the US-led "war on terror."

The beheading last month of a Japanese hostage in Iraq, after Koizumi rejected demands to withdraw Japanese troops, has fuelled a debate about whether the soldiers should extend their mission past December 14.

A recent Asahi Shimbun poll showed 63 percent of Japanese oppose extending the troop's one-year mission beyond next month.

Around 550 Japanese troops on a non-combat humanitarian mission are based in the southern Iraqi city of Samawa, Japan's first military deployment since World War II to a country where there is active fighting.

The chief of Japan's Defense Agency, Director-General Yoshinori Ono, told a morning television program that a decision on the mission would be made with "the security situation and prospect for Iraq's reconstruction" in mind.

He suggested troops could stay in Iraq until the end of next year.

"The multinational forces' term in Iraq ends at the end of next year according to UN Security Council resolution 1546," Ono said.

"By then, nation-building should be clear. That is the most important thing. That is why the new year's elections in Iraq must be made to succeed."

Main opposition leader Katsuya Okada of the Democratic Party of Japan renewed a call for the soldiers to be withdrawn.

"We have said the SDF should withdraw, even before December 14, and have opposed the dispatch. That has not changed," Okada told the same program.

The parade featuring 4,200 troops in red scarves and camouflage fatigues, along with 230 military vehicles and 60 aircraft, was held at the SDF's Asaka base just northwest of Tokyo.

Before Koizumi's arrival a sound similar to that of a gunshot was heard close to the base, police said.

Police began investigating whether the firing was the work of extremists after finding two metal tubes and a fuse in a wooded area pointed at the base, Jiji Press reported. No one was apparently injured, it said.

Police said they found a five centimeter (two-inch) diameter metal-like object less than a kilometer (0.6 miles) south of the base.

"We are looking into whether this object was fired," said Saitama police spokesman Yasuo Kazama.

Japan's military is called the Self-Defense Forces because its pacifist constitution rejects the use of force. The forces turned 50 years old on July 1 this year.

All rights reserved. � 2005 Agence France-Presse. Sections of the information displayed on this page (dispatches, photographs, logos) are protected by intellectual property rights owned by Agence France-Presse. As a consequence, you may not copy, reproduce, modify, transmit, publish, display or in any way commercially exploit any of the content of this section without the prior written consent of Agence France-Presse.