President Donald Trump signs the executive order to change the Defense Department to the War Department. (Photo: Reuters)

"It's a very important change" Trump said as he signed the executive order at a ceremony in the Oval Office. Defense Secretary Pete Hegseth, introduced as the Secretary of War by Trump, cheered the change, which he has long advocated. "We're going to go on the offense, not just on defense. Maximum lethality, not tepid legality," Hegseth said.

According to the White House, the order allows Hegseth and his deputies to officially use titles such as “Secretary of War” and “Deputy Secretary of War” in correspondence and public communication.

Trump’s move represented his latest effort to rebrand the US military, which has included his decision to preside over a military parade in downtown Washington, DC, and to restore the original names of military bases that were changed after racial justice protests in 2020.

Renaming is a rare occurrence and requires approval from Congress.

The Department of Defense was known as the Department of War until 1949, when Congress merged the Army, Navy, and newly created Air Force after World War II.

Historians say the new name was meant in part to emphasize that in the nuclear age, the US would focus on preventing wars rather than waging them.