U.S. President Joe Biden is expected to announce soon that he has chosen Gen. Charles Q. Brown Jr., the Air Force chief of staff, to become the country’s most senior military officer, according to two U.S. officials.

If he is formally nominated and approved by the Senate, Brown will succeed Gen. Mark Milley, whose term as chair of the Joint Chiefs of Staff expires at the end of September.

Brown would be only the second Black man to become chair, following Colin Powell, who served in that position during the presidencies of George H.W. Bush and Bill Clinton.