Washington ? The White House on Monday rebuffed calls for a staff shakeup, the firing of Karl Rove and an apology by President Bush for the role of senior administration officials in the unmasking of CIA operative Valerie Plame.

Three days after the indictment and resignation of Vice President Dick Cheney’s chief of staff, the administration said it would have to remain silent as long as there was an investigation of the leak and legal proceeding under way.

“We don’t want to do anything from here that could prejudice the opportunity for there to be a fair and impartial trial,” presidential spokesman Scott McClellan said.

Friday’s indictment of I. Lewis Libby and the continuing investigation of Rove were a blow to Bush’s already troubled presidency. The president’s approval rating has tumbled to the lowest point since he took office and Americans are unhappy about energy prices, the war in Iraq and economic uncertainties.

Republicans and Democrats alike have urged Bush to begin remaking his presidency by bringing in fresh advisers with new energy to replace members of a team worn down by years of campaigning and governing. But administration officials said that was not in the works.

Cheney promoted two of his advisers to fill the jobs handled by Libby, his confidant. David Addington, who has been the vice president’s legal counsel, was named chief of staff, while John Hannah, his deputy national security adviser, was named national security adviser. Both men have been on Cheney’s staff for more than four years.