Rice said the claim did not meet the standards for a presidential speech
US National Security Advisor Condoleezza Rice has defended a controversial claim that Iraq was seeking uranium from Africa, saying it was substantiated by several sources.
Nonetheless, she echoed President Bush's spokesman in saying that the allegation should not have been included in the president's State of the Union address in January.
In that speech, Mr Bush said: "The British Government has learned that Saddam Hussein recently sought significant quantities of uranium from Africa".
Ms Rice said: "The statement that he made was indeed accurate. The British Government did say that.
"Not only was the statement accurate, there were statements of this kind in the National Intelligence Estimate" - a reference to a classified document compiled by US agencies.
However, she stood by the position that it was a mistake to use it in the State of the Union address.
"We have a higher standard for presidential speeches than raw intelligence," Ms Rice said.
A more specific reference to Iraq's attempts to obtain uranium had been removed from an earlier speech at the CIA's request, she added.
The CIA has accepted the blame for allowing the claim to be used, even though the agency had long had doubts about its credibility.
Britain and the US both referred to Iraq's attempts to obtain uranium as they built the case for going to war over Saddam Hussein's alleged weapons of mass destruction.
But controversy has raged since the White House decided to back away from the claim, while the UK Government has continued to insist that it was well founded.
UK Prime Minister Tony Blair was dealt new criticism on Sunday by former chief UN weapons inspector Hans Blix for over-stating intelligence information.
And Mr Bush too is under new pressure over the issue as opinion polls show his popularity beginning to wane.
The uranium claim was first made public in a dossier on Iraq released by the UK in September last year.
But it has emerged that long before that, in February 2002, Ambassador Joseph Wilson - now retired - was sent to Niger by the CIA to verify the claim. He reported it to be unfounded.
In a letter to a senior MP on Saturday defending the claim, UK Foreign Secretary Jack Straw said his government had not been told of Mr Wilson's visit.
And he said separate intelligence which London had not passed to Washington meant that the UK remaining convinced Iraq had indeed tried to buy uranium in Niger.
In the letter to Donald Anderson MP, chairman of the House of Commons Foreign Affairs Committee, Mr Straw wrote:
"The CIA expressed reservations to us about this element of the September dossier...
"However, the US comment was unsupported by explanation and UK officials were confident that the dossier's statement was based on reliable intelligence which we had not shared with the US... A judgement was therefore made to retain it."
The prime minister's office said the extra intelligence had come from a foreign service and could not be disclosed.
Mr Anderson has called on the government to reveal its source to clear up the confusion.
British use of intelligence came under fire again on Sunday, in comments from former chief UN weapons inspector Hans Blix.
In his criticism, Mr Blix said the UK Government made a fundamental mistake when it declared that Saddam Hussein could deploy weapons of mass destruction in 45 minutes.
He told the British newspaper the Independent on Sunday that he believed Mr Blair had "over interpreted" the intelligence.