Donald Trump's national security aide Sebastian Gorka has become the latest presidential adviser to leave their White House post.
It was not immediately clear however whether Mr Gorka left out of choice or if he was ousted from his role.
Mr Gorka, a former editor for the conservative Breitbart News website, told news agencies that he has resigned his position, while a White House official stated he did not resign but "no longer works at the White House."
After his departure Mr Gorka declined to formally discuss the reasons he left the White House but did point toward excerpts from his resignation letter that were posted Friday evening by The Federalist website.
In the letter he wrote: "the individuals who most embodied and represented the policies that will 'Make America Great Again,' have been internally countered, systematically removed, or undermined in recent months."
He then added: "The best and most effective way I can support you, Mr. President, is from outside the People's House."
The national security aide was originally hired as a counter terrorism adviser and in his role made regular TV appearances as an outspoken defender of the Trump administration.
It is believed Mr Gorka's role saw him operate outside of the National Security Council and his exact responsibilities in the position were not clearly outlined.
Multiple recent White House departures
Mr Gorka is not the first of Mr Trump's aides to leave his White House post in recent months, as there have already been a string of high profile departures.
Most recently the president's chief strategist Steve Bannon, a key adviser in Trump's general election campaign, left the White House after the arrival of new chief of staff John Kelly.