Watch as Pete Hegseth has his nameplate outside of his office changed from Secretary of Defense to Secretary of War.
Video shared by Mr Hegseth on Friday (5 September) shows the switchover, which comes hours after Donald Trump signed an executive order which restores the original name of the government agency, which was ditched in 1947.
Signing the order 24 hours earlier, Mr Trump said: “So we won the first World War. We won the Second World War. We won everything before that and in between. And then we decided to go woke and we changed the name to Department of Defense. So we're going Department of War.”
The new name can only be used as a “secondary title” until Congress approves it, however the Pentagon's website and social media accounts have already switched to war.gov.