DONALD Trump's sacking of his chief of staff Reince Priebus is the latest and most dramatic step in his purge of influential Republican party figures.

The White House was plunged into fresh turmoil once more on Friday as Trump abruptly announced Homeland Security Secretary John Kelly's appointment, ending the turbulent six-month tenure of Priebus.

Priebus’s departure – announced by the US President on Twitter – comes just a week after embattled White House spokesman Sean Spicer finally stepped down.

Priebus, who has deep ties to House of Representatives speaker Paul Ryan, had grown increasingly isolated in the White House as past Republican National Committee colleagues and other allies have left or been pushed out.

These include former deputy chief of staff Katie Walsh, former communications chief Mike Dubke, press secretary Sean Spicer and press aide Michael Short.

Another early departure from the Trump White House was national security adviser Michael Flynn and the Trump also ousted FBI director James Comey. Trump has also lobbed Twitter insults at attorney general Jeff Sessions recently.

However, the sacking of Priebus represents the high watermark in a White House in what appears to be a deliberate purge of party loyalists tied to the Republican National Committee.

It comes after months of speculation about Priebus' fate. Trump tweeted his decision as he landed in Washington after a speech in New York in which he lavishly praised retired US Marines general Kelly's performance.

Priebus, the former Republican National Committee chief, had been a frequent target of rumours about his job security amid infighting and confusion within the White House and a long whispering campaign by Trump allies.

The failure of efforts to scrap Obamacare helped seal his fate,. He had also faced constant attack from his new colleague, White House communications director Anthony Scaramucci.

In an astonishing foul-mouthed public rebuke in an interview with the New Yorker magazine Scaramucci called Priebus, amid an avalanche of vulgarity, a "paranoid schizophrenic".

"I think the President wanted to go a different direction," Priebus told CNN just hours after his exit was announced, adding that he agreed the White House might well benefit from "a reset", and that "I'm always going to be a Trump fan. I'm on Team Trump."

Trump's Twitter announcement said: "I am pleased to inform you that I have just named General/Secretary John F Kelly as White House Chief of Staff. He is a Great American ... and a Great Leader. John has also done a spectacular job at Homeland Security. He has been a true star of my Administration."

He gave a backhanded salute to Priebus saying: "I would like to thank Reince Priebus for his service and dedication to his country. We accomplished a lot together and I am proud of him!"

Priebus, a political operative and lawyer, is expected to look for a corporate job or possibly write a book about his experience at the centre of the Trump storm.

As a former chairman of the Republican party, he acted as a bridge between the President and the party establishment.

But as one of the final establishment Republicans in the White House, he was a frequent target of barbs from Trump over not being an early backer of the celebrity businessman's candidacy.

As Homeland Security Secretary, Kelly took the lead on some of Trump's most controversial policies, including his executive orders suspending the admission of refugees and temporarily barring visitors from several Muslim-majority nations.

Those orders have been stripped down by courts pending a Supreme Court review in the autumn.

Trump’s administration includes a mix of former Democrats like his son-in-law Jared Kushner and Gary Cohn, the former president of Goldman Sachs, as well as Steve Bannon and speechwriter Stephen Miller.

Priebus’s removal is also unlikely to ease Trump’s relationships on Capitol Hill, particularly in the House of Representatives, which has been far more amenable to his agenda than the Senate.

Anthony Scaramucci profile Page 31