Hope Hicks, one of Donald Trump’s longest-serving aides, is resigning as White House communications director.
The 29-year-old, who was previously employed by the Trump organisation, has been one of the president’s most trusted advisors.
The former model served as Mr Trump’s press secretary during the 2016 election campaign.
It comes a day after Ms Hicks was interviewed for nine hours by the panel investigating Russian interference in the election.
She acknowledged to a House intelligence panel that she has occasionally told “white lies” for Mr Trump. But she said she had not lied about anything relevant to the Russia investigation.
In a statement, the president praised Ms Hicks for her work over the last three years and said he “will miss having her by my side”.
Ms Hicks said in a statement: “There are no words to adequately express my gratitude to President Trump.”
Before Wednesday’s announcement, Ms Hicks is reported to have been increasingly feeling the stress of her position.
Ms Hicks, who has long tried to avoid media attention, was thrust into the spotlight recently when it was revealed she had been dating former Staff Secretary Rob Porter. He left the administration after accusations that he had abused his two ex-wives became public.
Ms Hicks helped craft the White House’s initial supportive response.
White House press secretary Sarah Huckabee Sanders told reporters that Ms Hicks would remain at the White House “for several weeks” and denied that her decision to leave had anything to do with her lengthy evidence before the House Intelligence Committee.
“Don’t try to read more into it than exists,” Mrs Sanders said. “This is something that she’s been thinking about for a while.”