White House chief of staff Andy Card has resigned and will be replaced by budget director Josh Bolten, an administration official said Tuesday. President George W. Bush was expected to announce the shake up during a meeting with reporters later Tuesday morning in the Oval Office of the White House. The move comes amid a sharp decline in Bush's approval ratings and calls from Republicans for the president to bring in new aides with fresh ideas and new energy. Card came to Bush recently and suggested that he should step down from the job that he has held from the first day of Bush's presidency, said the administration official. Bush decided during a weekend stay at the Camp David presidential retreat to accept Card's resignation and to name Bolten as his replacement, said the source who spoke on condition of anonymity because he did not want to pre-empt the president.