It's unclear who'll take over at the Pentagon and the military services when the top leaders all step down Monday as President-elect Donald Trump is sworn into office.

Trump has often criticized his former top general, whose portrait was taken down at the Pentagon just after the new administration took office.

A portrait of retired Gen. Mark Milley, a target of President Donald Trump's wrath, disappeared from a Pentagon hallway hours after the inauguration.

The Pentagon on Monday removed the portrait of Mark Milley, the retired Army general and former chairman of the Joint Chiefs of Staff, according to two Reuters witnesses, in a move that happened within two hours of President Donald Trump's inauguration.

A portrait of former Chair of the Joint Chiefs of Staff Gen. Mark Milley has vanished from the Pentagon barely two weeks after being installed, Politico reported on Monday. New Pentagon officials "did not explain the portrait’s removal,