The White House says it still supports World Bank head Paul Wolfowitz but adds that "all options are on the table".
Paul Wolfowitz will have to appear before the 24-member board
"We've made clear that we support Paul Wolfowitz," said spokesman Tony Snow, but added that the bank's "best interests" also had to be served.
A day earlier, the bank had said Mr Wolfowitz broke its rules by helping secure a pay rise for his girlfriend.
The comments come in advance of Mr Wolfowitz's hearing before the bank, which will decide his future there.
Mr Wolfowitz is set to appear before the bank's 24-member board later on Tuesday.
The board has the power to dismiss him or report a lack of confidence in his leadership or simply reprimand him.
'Not a firing offense'
On Monday, a panel of World Bank executives said Mr Wolfowitz provoked a "conflict of interest" at the bank, by breaking its code of conduct and violating the terms of his contract.
Mr Wolfowitz has faced calls for him to step down since details emerged about his role in securing a pay rise for his partner, Shaha Riza, who used to work at the bank.
Mr Snow told journalists at the White House that Mr Wolfowitz agreed "a lot of mistakes were made" in the process, but they were not a "firing offence".
"There are two tracks going on right now," Mr Snow added. "Number one, we've made clear that we support Paul Wolfowitz. And the separate track is what is gonna be best for the institution."
It was at that point that the White House's support for Mr Wolfowitz appeared to waver.
"At some point in the future there are going to be conversations about the proper stewardship of the World Bank," Mr Snow said.
"In that sense... all options are on the table,"
When Mr Wolfowitz was appointed president of the World Bank in 2005, Ms Riza was transferred to work for the US Department of State, to avoid any conflict of interest.
But her salary rose quickly to about $193,000 (£98,000) - more than the $186,000 that Secretary of State Condoleezza Rice receives before tax.
The World Bank has since been investigating the extent of Mr Wolfowitz's role in securing the pay increase.
Mr Wolfowitz has received the backing of senior figures in the US administration, including an endorsement by Vice President Dick Cheney.
But he is less popular with European governments, which hold key positions on the board of the bank.