Chief of Staff John Kelly to step down by year-end: Trump

US President Donald Trump on Saturday said his Chief of Staff John Kelly would be leaving the White House by the end of this year, the latest in the series of reshuffle in the Trump administration.

A retired marine general, 68-year-old Kelly has been Trump's Chief of Staff since July 31, 2017. In the first seven months of the Trump administration, he was the secretary of Homeland Security.

There were reports that the relationship between Trump and Kelly has deteriorated to such an extent that the two were no longer on speaking terms.

"John Kelly will be leaving I don't know if I can say 'retiring'. But, he's a great guy. John Kelly will be leaving at the end of the year," Trump told reporters at the White House.

Kelly, who was brought in by Trump after he fired Reince Priebus, has been instrumental in bringing in a sense of discipline inside the White House.

No replacement of Kelly has been named yet.

"We will be announcing who will be taking John's placeI shall be announcing that over the next day or two. But, John will be leaving at the end of the year. He has been with me almost two years now," Trump said.

Earlier in the day, Trump nominated General Mark Milley as his next Chairman of the Joint Chiefs of Staff, the nation's top military advisor.

If confirmed by the Senate, Gen Milley would replace General Joe Dunford who is scheduled to retire next summer. Milley currently is Chief of Staff of the Army.

Trump described Gen Milley as a "great gentleman and a great patriot".