PRETORIA, South Africa (CNN) -- President Bush said Wednesday that he was "absolutely confident" in his decision to remove Saddam Hussein from power, but he refused to be drawn into the controversy over an assertion he once made that Iraq sought to buy uranium from Africa.
"There is no doubt in my mind that Saddam Hussein was a threat to the world peace, and there is no doubt in my mind that the United States, along with allies and friends, did the right thing in removing him from power," Bush said during a joint news conference with South African President Thabo Mbeki.
Bush also said that his predecessor, President Clinton, raided Iraq in 1998 "based upon the very same intelligence."
Many Democrats are calling for an investigation into Bush's claim in his State of the Union address that Iraq tried to buy large amounts of uranium in Africa -- an allegation that has since been proven to be false.
A Bush administration official said the president never would have included the information in his speech if his advisers had known it was false. Other U.S. officials said the White House had a report citing a former U.S. ambassador that the intelligence was bogus.
U.S. Sen. Carl Levin of Michigan, ranking Democrat on the Senate Armed Services Committee, said the latest White House statements "only reinforce the importance of an inquiry into why the information about the bogus uranium sales didn't reach the policymakers during 2002, and why, as late as the president's State of the Union address in January 2003, our policymakers were still using information which the intelligence community knew was almost certainly false."
U.S. Sen. Ted Kennedy, a Massachusetts Democrat, used even stronger language.
"It's bad enough that such a glaring blunder became part of the president's case for war. It's far worse if the case for war was made by deliberate deception," Kennedy said.
"It's more important than ever that Congress conduct a real investigation into the use of intelligence sources as a justification for war. The American people deserve to know whether the president is making war and peace decisions based on reliable information. We cannot risk American lives because of shoddy intelligence or outright lies."
Senate Republican Conference Chairman Rick Santorum of Pennsylvania defended the administration, saying it has been "very forthright ... as to what they knew and when they knew it, and I think they had the best information that they thought was reliable at the time the president said it."
Senate Democratic Leader Tom Daschle of South Dakota said that "a full investigation of the facts surrounding this situation be undertaken, the sooner the better."
U.S. Sen. John Kerry of Massachusetts, a Democratic presidential candidate, also called for an investigation.