Donald Trump has forced Defense Secretary Jim Mattis out of his role two months early, by announcing his successor will take up the role as of the 1st January.
General Mattis handed in his resignation at the end of last week, shortly after Trump announced his decision to withdraw all US troops from Syria.
It is believed that his departure from the role is due to policy differences with President Trump.
In his resignation letter Mattis says the President should appoint someone whose “views are better aligned with yours”.
Mattis had previously said he was happy to stay in the role until February but now Deputy Defense Secretary Patrick Shanahan will take over on the 1st January.
The President tweeted the announcement describing Mr Shanahan as having “a long list of accomplishments”.