White House chief of staff John Kelly is expected to leave in the coming days, NBC News reported on Friday.

Vice President Mike Pence's chief of staff Nick Ayers is among the candidates who could succeed Kelly. Speculation has swirled about the retired Marine Corps general's exit for months amid disagreements with President Donald Trump.

Kelly has increasingly clashed with both national security officials and first lady Melania Trump, NBC reported last month. Trump has reportedly shown frustration with Kelly during the chief of staff's tenure.