Trump announced Monday that he fired Mark Esper as his defense secretary and said that Christopher Miller would serve as acting secretary of the Defense Department. “I am pleased to announce that Christopher C. Miller, the highly respected Director of the National Counterterrorism Center (unanimously confirmed by the Senate), will be Acting Secretary of Defense, effective immediately,” Trump tweeted, announcing his first personnel move since losing the presidential election. He added, “Chris will do a GREAT job! Mark Esper has been terminated. I would like to thank him for his service.”

Trump announced Monday that he fired Mark Esper as his defense secretary and said that Christopher Miller would serve as acting secretary of the Defense Department.

“I am pleased to announce that Christopher C. Miller, the highly respected Director of the National Counterterrorism Center (unanimously confirmed by the Senate), will be Acting Secretary of Defense, effective immediately,” Trump tweeted, announcing his first personnel move since losing the presidential election.

He added, “Chris will do a GREAT job! Mark Esper has been terminated. I would like to thank him for his service.”