Mr. Gorka, 46, has also been accused of having links to far-right groups in Europe. He is a former editor at Breitbart News, a right-wing website, and a friend of Stephen K. Bannon. Mr. Bannon, who was until last week Mr. Trump's chief strategist, has since returned to Breitbart News as executive chairman.
An American citizen who was born in Britain to Hungarian parents, Mr. Gorka made a habit of assailing the news media for its coverage of Mr. Trump, insisting that reports of turmoil in the White House had "almost no resemblance to reality."