"It has become an enormously overblown issue," White House national security adviser Condoleezza Rice told CNN. "The president of the United States did not go to war because of the question of whether or not Saddam Hussein sought the uranium in Africa," she said. Earlier, on "Fox News Sunday", she dismissed the notion as "ludicrous."

On Friday, CIA director George Tenet took responsibility for the now-discredited allegation in the president's State of the Union speech in January.

One leading Republican senator said Tenet should quit over his role in the matter.

"Somebody ought to be accountable," Richard Shelby, the ranking Republican on the powerful Senate Intelligence Committee told CNN. "If I were the president, he wouldn't be there."

The White House admitted Tuesday that the remark by Bush, stating that Baghdad had sought "significant quantities of uranium from Africa," overstated Saddam's alleged efforts to obtain uranium for nuclear arms.

Other congressional lawmakers meanwhile said they would await the findings of an investigation into the matter before taking a position on Tenet's future. The Senate, by voice vote, has approved a probe into the matter.

"Well, I would like to wait for the end of the investigation to reach a conclusion as to whether Tenet should go. I'm obviously dissatisfied with him in this regard, but also in other aspects as well," Senator Carl Levin, the ranking Democrat on the Senate Armed Services Committee, told CNN.

Levin directed fire, however, at how the remarks came to be included in a presidential speech to the nation.

"That is highly misleading. It is intended to create a false impression. And someone in the White House was pushing the CIA," the Democratic senator said.

In January's State of the Union speech, Bush attributed the claim to the British government. White House officials said Sunday the intelligence information backing the statement was not strong enough to include in a major presidential speech.

The controversy has sparked a spirited debate in the United States over the reasons given by Bush for going to war, as well as over the quality of US intelligence and whether it was manipulated for political purposes.

Defense Secretary Donald Rumsfeld also took pains to explain that while the statement should not have been included in the speech, it was technically correct in referring to British intelligence that London has not refuted.

However, he also admitted that the statement should not have been included in the speech, as US intelligence had not confirmed it.

The "National Intelligence Estimate" said Iraq tried to purchase up to 500 tons of uranium oxide for its nuclear program from the west African country of Niger.

The White House admitted the charge stemmed from documents since discovered to be forgeries alleging that Iraq sought uranium "yellowcake" from Niger.

Officials insisted that Bush made the statement in good faith at the time.

A new poll, published by Newsweek, found only 53 percent of respondents approve of Bush's handling of Iraq, down 21 percent since April.

The furor over the uranium claim only deepens the skepticism caused by US forces' failure so far to find any definitive proof of chemical or biological weapons in Iraq, which were one of Bush's main justifications for the war.

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