​​​​​​​WASHINGTON

The Trump administration’s effort to formally rename the Department of Defense as the "Department of War" could carry a price tag of up to $125 million, the Congressional Budget Office (CBO) said Wednesday.

Director Phillip Swagel said in a letter that, according to the CBO's assessment, it would cost about $10 million for a "modest implementation" of the order if the name change primarily occurred within the office of Secretary of Defense Pete Hegseth.

President Donald Trump signed an executive order in September for the renaming and signaled he would turn to Congress to make the change official.

Hegseth installed a new bronze "Department of War" plaque in November at the Pentagon's entrance.

"Costs would be at least a few million dollars if DoD phased in a minimal implementation, but they could be as large as $125 million if the name change was implemented broadly and rapidly throughout the department," Swagel wrote.

"A statutory renaming could cost hundreds of millions of dollars depending on how Congress and DoD chose to implement the change."

He added that the CBO's estimates carry significant uncertainty because the Defense Department declined to provide details about how it plans to implement the order.

Trump said he would work with Congress to codify the change, but claimed it is unclear if lawmakers would have to act to make it official.

Congress is given the authority under the Constitution to create, establish and rename federal agencies.

The Department of War was established in 1789, 13 years after the US Declaration of Independence was adopted in 1776. It was renamed under legislation signed by President Harry Truman shortly after the conclusion of World War II, when many hoped for the end of global conflict.