A powerful committee of the US Senate has given the Central Intelligence Agency 48 hours to supply the files it gathered on Iraq prior to the war.
Opposition to Bush's policy in Iraq is becoming more vocal
US media say a forthcoming Senate Intelligence Committee report on Iraq is likely criticise the CIA and its Director, George Tenet.
Correspondents say the charges against the CIA may be rooted in domestic politics, as a poll shows decreasing support for the administration's handling of Iraq.
Despite the rising criticism, President George W Bush has defeated moves in Congress to turn half of his reconstruction package for Iraq into a loan.
The Senate Intelligence Committee - which includes both Republicans and Democrats - said the CIA had until noon (1700 GMT) on Friday to produce its files on Iraq and schedule interviews with its operatives.
It also demanded that Mr Tenet appear in person before its panel, although it set no date for the hearing.
Tenet, a Clinton-era figure, is under pressure
In a letter to the CIA, senior members of the committee highlighted the disputed claim that Iraq sought uranium from Niger.
Some of the documents supposedly backing up the claim are now believed to have been forgeries.
The committee's forthcoming report is expected to accuse the CIA and Mr Tenet of overstating the case against Saddam Hussein.
However, the BBC's David Bamford in Washington says some Democrats are suspicious that Mr Tenet, who was appointed under former President Bill Clinton, is being used as a scapegoat to deflect criticism away from the White House.
The deadline was issued as congressional negotiators rejected a proposal that Iraq should repay 50% of the reconstruction aid it receives from Washington.
President Bush had requested $20.3bn for Iraqi reconstruction.
Iraq is in urgent need of reconstruction aid
The House of Representatives had approved the request, but the Senate had voted to convert half of the amount into loans, to be repaid through Iraq's future oil output.
This was strongly opposed by the White House, who said loans would burden Iraq and slow efforts to stabilise the country.
President Bush had threatened to veto the entire $87.5bn package for Iraq and Afghanistan unless its request on Iraqi reconstruction was approved.
On Wednesday, the House-Senate panel - convened to reconcile the two versions of the bill - agreed that none of the reconstruction aid should be repaid.
However, the total was reduced to $18.5bn.
The decision paves the way for Congress to approve the entire $87bn package as early as Thursday.
Meanwhile, controversy is raging over President Bush's speech on an aircraft carrier in May declaring major combat operations over.
Behind him was a banner proclaiming "mission accomplished".
Critics have seized on the banner
Earlier this week, the president said the ship's crew had been responsible for the banner. But the White House now says it helped produce it.
The BBC's Rob Watson says that trivial as it may seem, the issue has been leapt on by those who argue the administration never really prepared the American people for the bloody post-war phase.
The president insists he warned from the start of the hard work and dangers ahead.
But, our correspondent adds, he must be concerned about latest poll figures, which suggest support for the war has dropped from 71% in April to 52% now.