Current CIA director Leon Panetta, who President Barack Obama has selected to replace Gates, will take up his duties the following day, assuming he is confirmed by the US Senate, the official said.
The official, speaking on condition of anonymity, said Gates would go likely go down in history as likely ‘one of the best’ defense secretaries to serve a president of the United States.
Gates took office in December 2006 during the Republican administration of president George W. Bush, and was asked to stay on by Obama, and has been a hugely influential member of the new US leader's national security team.
The official said that Panetta, a former congressman and White House chief of staff, would bring decades of experience both inside and outside Washington to his new job.
He also confided that Panetta had not wanted to leave the CIA, but had decided he had to heed Obama's call.
‘Leon loved being director of the CIA and it shows. It was a difficult decision for him to leave the agency.’