Downer said before he left for Washington for talks with senior US officials on the war and its aftermath there was "no danger" that coalition troops would be withdrawn.

He acknowledged Iraqi tactics such as suicide bombings could extend the military campaign, but denied Iraq's war strategy would change coalition military tactics or lessen the emphasis on minimising civilian casualties.

"I know that puts us at some disadvantage," he said. "It does mean that the war will take a little longer than would otherwise have been the case."

But he told reporters here that now the conflict is underway, it is important to support Australian and coalition troops and to ensure the war ended swiftly and successfully.

There was no plan to withdraw the Australian contingent before the end of the conflict, which he warned would be "ignominious and foolish".

"I think it's terribly important now the war is underway we ... make sure that it's prosecuted successfully with the minimum of civilian casualties and that it can be over as quickly as possible," he said.

Downer said the notion that "we should abandon the conflict against Iraq and give Saddam Hussein the most monumental victory imaginable is absolutely out".

"There's no danger of that happening," he added.

His visit to Washington was hastily arranged after Prime Minister John Howard declined an invitation to attend a war summit with President George W. Bush and Britain's Prime Minister Tony Blair last week.

Downer will hold talks with US Secretary of State Colin Powell, National Security Adviser Condoleezza Rice and with UN officials.

High on the agenda will be the reconstruction of post-war Iraq as well as humanitarian aid for the Iraqi people, Downer said.

Australia has committed 2,000 military personnel to the war.

Defence Minister Robert Hill said Sunday that the guerilla tactics were another challenge for coalition forces and may have caught the United States off-guard.

"I think they underestimated the role of the militias within the smaller cities and towns," Hill said.

"They've fought hard and they certainly have resulted in some delays of progress."

WAR.WIRE