President Trump's deputy assistant, Sebastian Gorka, resigned from his White House post Friday.

"[G]iven recent events, it is clear to me that forces that do not support the MAGA promise are – for now – ascendant within the White House," Gorka wrote in his resignation letter. "As a result, the best and most effective way I can support you, Mr. President, is from outside the People's House."

Gorka went on to say he did not believe Trump's "Make America Great Again" agenda could be carried out.

"Regrettably, outside of yourself, 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. This was made patently obvious as I read the text of your speech on Afghanistan this week…" Gorka wrote. "The fact that those who drafted and approved the speech removed any mention of Radical Islam or radical Islamic terrorism proves that a crucial element of your presidential campaign has been lost.

"Just as worrying, when discussing our future actions in the region, the speech listed operational objectives without ever defining the strategic victory conditions we are fighting for. This omission should seriously disturb any national security professional, and any American who is unsatisfied with the last 16 years of disastrous policy decisions which have led to thousands of Americans killed and trillions of taxpayer dollars spent in ways that have not brought security or victory," Gorka added.

Though the original story from the Federalist about Gorka's exit says he resigned, a White House official rejected that claim.

"Sebastian Gorka did not resign, but I can confirm he no longer works at the White House," said a White House official.

However, in a brief follow-up exchange with the Washington Examiner, Gorka asserted that he did indeed quit, despite what the White House had said.

"How disappointing. I resigned," he said in a text.

In a separate text message Gorka said he told White House chief of staff John Kelly "today and emailed him today" about his resignation. "It's very disappointing that someone wished to spin this," he added.

Three Democratic senators recently asked the Trump administration to disclose whether Gorka had lied about membership to the Vitezi Rend, a far-right anti-Semitic Hungarian group, when he became a U.S. citizen.

The question became a bigger deal as a result of President Trump's response to the deadly Aug. 12 incident in Charlottesville, Va. Democrats accused Trump, as well as former White House chief strategist Steve Bannon and Gorka, of being racists. Gorka had previously worked under Bannon at Breitbart News.

The heads of four minority House caucuses called on Trump earlier this month to remove Gorka, along with Bannon and senior policy adviser Stephen Miller, from his administration.

Sarah Westwood and Gabby Morrongiello contributed to this report.