Sebastian Gorka, the brusque national security aide to President Donald Trump, reportedly resigned his post as deputy assistant to the president late Friday.

The Federalist reports Gorka wrote a scathing resignation letter that sharply criticized the president’s newly unveiled strategy for the war in Afghanistan, and savaging White House rivals who he claims oppose the Trump agenda.

“[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. “As a result, the best and most effective way I can support you, Mr. President, is from outside the People’s House.”