President Donald Trump is expected to sign an executive order tomorrow renaming the Department of Defense the Department of War, a White House official and sources familiar with a draft of the executive order told ABC News. 

The formal renaming of the department would require Congress to act, but the order is expected to say the new name can be used in official correspondence and ceremonial contexts and non-statutory documents. 

The Secretary of Defense may also use the title of Secretary of War, the White House confirmed. 

Trump has teased the renaming for months and last month told reporters he didn't think he needed congressional approval to change the name. 

“We’re just going to do it. I’m sure Congress will go along if we need that. I don’t think we even need that,” Trump said last month. 

This is a developing story and will be updated.