US President Donald Trump has sacked his White House chief of staff, Reince Priebus.
In a series of tweets, Mr Trump said John F Kelly would take over the role.
He also thanked Mr Priebus for his "service and dedication to his country."
"We accomplished a lot together and I am proud of him!", he 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....
— Donald J. Trump (@realDonaldTrump) July 28, 2017
...and a Great Leader. John has also done a spectacular job at Homeland Security. He has been a true star of my Administration
— Donald J. Trump (@realDonaldTrump) July 28, 2017
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!
— Donald J. Trump (@realDonaldTrump) July 28, 2017
The move comes after Anthony Scaramucci was appointed as new communications chief at the White House.
In a bizarre rant to a journalist on Thursday, Mr Scaramucci called Mr Priebus a "paranoid schizophrenic" and threatened to "eliminate everyone" in his communications team.
The communications director was believed to have had an intense rivalry with Mr Priebus and Sean Spicer - who resigned his post as press secretary when Mr Scaramucci was hired by Mr Trump one week ago.
During much of the phone call, Mr Scaramucci accused Mr Priebus of attempting to obstruct his success in the White House - saying he had "c***-blocked" and orchestrated leaks against him.
As the conversation continued, Mr Scaramucci's tone became more aggressive, and he began referring to himself in the third person as "the Mooch," suggesting he had "nailed" his colleagues for what he believed to be potentially unlawful behaviour.
