Claire Buchan said the administration was discussing the exact amount to be requested with US civil administrator in Iraq, Paul Bremer and with military officials.
"We don't have the numbers at this point, and until we have responsible numbers, we're not going to go to Congress," she told reporters in Texas on Wednesday while the president relaxed on his nearby ranch.
"Victory in Iraq is critical, it's critical to the war on terrorism," she said. "We will do everything to ensure that the resources are there to finish the job and to do that effectively."
But speaking to the Washington Post, Paul Bremer said that “tens of billions of dollars” would be needed.
Bremer said that meeting Iraq's electrical demand alone would require two billion dollars and 12 months of work, while providing clean water would cost $16 billion over four years.
"We don't have the numbers at this point, and until we have responsible numbers, we're not going to go to Congress"
White House Spokeswoman
In addition, other top administration officials have said the White House will seek billions in supplemental financing for the reconstruction of Iraq.
But Bush had earlier said that Iraqi oil sales would pay for its own rebuilding.
In other developments, Bush announced that he was invoking his perogative to limit a planned January 2004 pay raise for many federal workers, saying it "would interfere" with the war on terrorism.
"Such cost increases would threaten our efforts against terrorism or force deep cuts in discretionary spending or federal employment to stay within budget," he said in the statement.
The United States is also spending an estimated four billion dollars a month on the military occupation of Iraq.