The chief of staff is a political appointee of the president of the United States who does not require Senate confirmation, and who serves at the pleasure of the president. While not a legally required role, all presidents since Harry S. Truman have appointed a chief of staff; with the exception of John F. Kennedy and Lyndon Johnson, whose equivalent appointments were to the office of White House appointments secretary, a role that would later be subsumed into that of chief of staff.