Donald Trump to rename the Department of Defense as the Department of War

The move could cost tens of millions of dollars.

On Friday, the president will sign an executive order for the new name to be used as a secondary title for the government's biggest organisation.

At the same time, defence secretary Pete Hegseth will be known as the "secretary of war" in official communications and ceremonies.

Renaming the department begin with Trump's executive order instructing Hegseth to start the process, which will ultimately need congressional approval.

The new name will hark back to the 1940s, when the Pentagon was called the War Department. It had this name until 1949, when it was changed to focus on preventing conflict after World War Two.

Speaking from the Oval Office on Thursday, Trump questioned the current department name, asking: "What are we defence, why are we defence?"

He said the "Department of War" had a "stronger sound."

Trump claimed the US "used to win wars all the time" and "won everything", adding: "Defence? I don't want to be defence only. We want defence, but we want offence to if that's okay."

The move looks set to be a colossal waste of money though. Sky News reports the name change could cost tens of millions of dollars due to the potential replacement of letterheads and building signs in America and at military bases across the globe.

Pointing this out, Democratic senator Tammy Duckworth asked why the money was not being put "toward supporting military families or toward employing diplomats that help prevent conflicts from starting in the first place?"