Defense Secretary Jim Mattis will step down from his position early next year, President Donald Trump announced Thursday evening.

“General Jim Mattis will be retiring, with distinction, at the end of February, after having served my Administration as Secretary of Defense for the past two years,” Trump tweeted.

Trump touted the “tremendous progress” that has been made during Mattis’ tenure at the helm of the Defense Department and thanked Mattis for his service.

Trump said a successor “will be named shortly.”