US President Donald Trump is directing that the Pentagon be known as the Department of War.
He will sign an executive order on Friday for the Department of Defense to use the new name as a secondary title and for Defence Secretary Pete Hegseth to be known as Secretary of War.
The Pentagon - which oversees the US armed services - is the successor to the War Department, which was first established as a cabinet-level agency in 1789 and existed until 1947.
The responsibility of creating executive departments rests with the US Congress, meaning that an amendment would be required to legally change the department's name.
The BBC has seen the text of the executive order, which says: "The name 'Department of War' conveys a stronger message of readiness and resolve compared to 'Department of Defense,' which emphasizes only defensive capabilities."
