President George W Bush
has backed the director of the US Central Intelligence Agency, George Tenet, amid controversy over claims that Iraq tried to buy nuclear material from Africa.
Tenet says the CIA made a mistake
Mr Tenet has acknowledged that his organisation was wrong to let President Bush tell the American people that Iraq was trying to acquire uranium for use in nuclear weapons from the state of Niger.
In a statement issued on Friday, he admitted that CIA officials had failed to prevent the allegation from being inserted into the president's State of the Union address in January, despite having doubts about its validity.
Mr Bush, speaking in the Nigerian capital Abuja, said: "I've got confidence in George Tenet. I've got confidence in the men and women who work at the CIA and I... look forward to working with them."
He added that he now considered the matter closed.
The issue has sparked controversy in the United States, with opposition Democratic Party politicians saying that many questions remain unanswered and demanding an inquiry.
It has also overshadowed the last two days of Mr Bush's five-nation African tour.
The BBC's Mike Fox says the White House has clearly shifted into damage limitation mode, with Mr Tenet apparently singled out to be the fall guy.
President Bush has emphatically denied that he knowingly gave out false information.
In his January address, Mr Bush said: "The British Government has learned that Saddam Hussein recently sought significant quantities of uranium from Africa."
Mr Tenet, in his statement, said that although the president's words were factually correct - in the sense that they attributed the allegation to the British Government - they should never have been included in the speech, given the long-held doubts that US intelligence had about Britain's claims.
The British Government stands by the allegation. Prime Minister Tony Blair's office says Britain had separate intelligence from that referred to by the Americans, but is refusing to reveal the source of the information.
Senior US Democrats are demanding to know what Mr Bush knew about the allegation, and who pressed for it to be included in the State of the Union address, despite the doubts of US intelligence.
One of the contenders for the Democratic presidential nomination, Howard Dean, has called for resignations over the issue.
"This government either is inept or simply has not told us the truth," he said.
Senator Joseph Lieberman, another Democratic presidential hopeful, said the controversy "breaks the basic bond of trust we
must have with our leaders in times of war and terrorism".
The latest US opinion polls suggest that a majority of Americans now believe the White House exaggerated the threat posed by former Iraqi leader Saddam Hussein, who was deposed by the US-led invasion of Iraq.