"This administration will deal with gathering dangers where we find them," Bush said on Friday, adding that he was not worried about a new CBS News-New York Times poll that said 53% of Americans doubted whether the Iraq war was worth the cost.
The suspected existence of biological, chemical and nuclear weapons that posed an imminent danger to the Western world was one of the main justifications for the US-led war that toppled the Iraqi leader.
However David Kay, the head of the US team of 1200 experts scouring Iraq for WMD, has found no such weapons.
"We have not found at this point actual weapons," Kay told reporters on Thursday after giving closed door briefings to the Senate and House of Representatives intelligence committees on the work of the Iraq Survey Group.
Neither was his team able to confirm pre-war intelligence stating that Iraqi military units were prepared to use chemical warfare agents against US forces.
But Bush cast aside the author of the report's caution in a rare public appearance before leaving for a day-long fundraising swing. "He's saying Saddam Hussein was a threat, a serious danger," Bush said.
Little or no capacity
David Kay's report contains no clear evidence of Iraqi WMDs
In a report to the committees that was released in declassified form, Kay's team found that Iraq had little or no capacity to produce chemical warfare agents before the war because of damage inflicted by US air strikes and years of sanctions.
Kay insisted the findings did not mean the United States had concluded there were no weapons. "My advice to everyone is still don't be surprised by surprises in Iraq," he said.
It would take between six and nine more months to give a firm indication of the state of the Iraqi weapons program, he said.
The search had already cost $300 million and the administration plans to ask for $600 million more, the New York Times reported.
Kay's team did find that Saddam had not given up his goal to acquire weapons of mass destruction, and that the Iraqis were well advanced in developing missiles with ranges at least up to 1000 km (620 miles), well in excess of the 150km (90-mile) range allowed under UN sanctions.
Asked about Kay's remarks, a senior White House official who declined to be named replied, "Keep in mind it is a progress report, not a final reckoning of Iraq's weapons of mass destruction programmes."
Australian Prime Minister John Howard said on Friday he had no regrets over Australia's role in the US-led war on Iraq, despite Kay’s failure to unearth any of the weapons cited as the reason for the invasion.
"You make judgements on the basis of the information available at the time you are required to make those judgements and the judgement was valid, the judgement was justified and it's a judgement I totally stand by and do not retreat from one iota," he said.
"(The report) confirms how dangerous and deceitful the regime was, and how the military action was indeed both justified and essential to remove the dangers"
UK foreign minister
In London, British Foreign Minister Jack Straw said in a statement that Kay's report "confirms how dangerous and deceitful the regime was, and how the military action was indeed both justified and essential to remove the dangers."
Britain was the main US ally in the Iraq war, and Prime Minister Tony Blair also faces widespread criticism over the evidence used to back the case for the invasion.