Pentagon and White House officials say "professional obligations" may delay Robert Gates' arrival at the Pentagon as the new secretary of defense.
Normally, a swearing in ceremony would take place almost immediately after confirmation, but a senior White House official tells ABC News that when it comes to Gates, "there might be a little bit of a lag so he can take care of some professional commitments."
The Senate Armed Services Committee has scheduled confirmation hearings for next week; assuming those go well, Gates is expected to be confirmed by the Senate the week of Dec. 11.
Senate Democrats, eager to hasten the departure of outgoing Defense Secretary Donald Rumsfeld, are working with Republicans to speed up the confirmation process.
Pentagon spokesman Eric Ruff says Gates may have some obligations related to his duties as the outgoing president of Texas A&M University.
"He may have a couple of commencements to go to," Ruff said.
Newsweek quoted an unidentified White House official, saying Gates would be sworn in as defense secretary "in the new year." Such a move would allow Rumsfeld to become the longest-serving defense secretary in American history (on Dec. 29 he would surpass the tenure of Robert McNamara, another former business executive who led the Pentagon during a long and unpopular war).
Yet another unidentified White House official tells ABC News that Gates' confirmation would not be delayed that long.
"If the Senate confirms Gates quickly, we expect to swear him in well before the new year," the official said.
That means, although Rumsfeld's departure may be slightly delayed, he is unlikely to break McNamara's record.
Does Rumsfeld care about breaking McNamara's record?
"I can assure you, that is not a factor in the secretary's mind," said Ruff.
Another Pentagon official tells ABC News that Rumsfeld "thinks the new secretary should be sworn in as soon as practicable."
This official says Rumsfeld would be "appalled" if anybody tried to delay his departure so he could surpass McNamara as the longest-serving defense secretary.