"I think they will be discovered eventually. Over time, the authorities will do their best to find them," Koizumi told a legislative session as the leaders of the opposition parties took turns to grill him.

"We must closely monitor what sort of weapons will be discovered," he said.

His answers prompted jeers from opposition lawmakers, who charged he was simply following Washington's orders in expressing support for the war without proof Iraq possessed viable weapons of mass destruction.

"What will do you if no weapons of mass destruction turn up," asked Naoto Kan, head of the Democratic Party of Japan. "You supported the war, saying there were weapons of mass destruction."

"Based on what specific, concrete factors, did you make the clear judgement that weapons of mass destruction were there?" said Communist Party leader Kazuo Shii.

Koizumi, who declared his support for the United States only an hour after President George W. Bush announced the war had begun, despite overwhelming public opposition, did not directly respond to Shii's question.

The prime minister merely said many countries suspected Iraq of possessing weapons of mass destruction as Iraq used chemical weapons in the past, that it failed to show evidence that it destroyed weapons and that Iraq failed to work with international inspectors, among other things.

"Considering all those factors, many countries came to suspect that (Iraq) held weapons of mass destruction and chemical and biological weapons," Koizumi said.

The comment provoked uproar among opposition lawmakers, who said his answers did not justify his support for the war.

"You are simply gulping down what the United States tells you," Shii said.

Koizumi is the latest among world leaders who committed their forces or were quick to back the US-led war which was begun without the blessing of the United Nations Security Council to feel the heat from domestic opposition politicians.

The administration of US President George W. Bush has come under heavy fire from opposition Democrats and other critics who charge that it exaggerated the threat Iraq posed in order to win public support for the campaign.

British and Australian prime ministers Tony Blair and John Howard also have been made to squirm over claims that they exaggerated the threat posed by Saddam Hussein in order to justify sending troops in support of the US-led invasion.

US-led forces have yet to locate conclusive evidence backing the US leader's central case for war: that Saddam Hussein possessed chemical and biological weapons, pursued nuclear arms, and might one day have armed terrorists with them.

WAR.WIRE