White House Communications Director Hope Hicks plans to resign, according to ABC News sources

WASHINGTON (KGO) -- Sources with direct knowledge confirm to ABC News, Hope Hicks, the president's longest serving aide and current communications director plans to resign her post in the coming weeks.

The news comes a day after Hicks was interviewed for nine hours by the panel investigating Russia interference in the 2016 election and contact between Trump's campaign and Russia.

VIDEO: Hope Hicks and Trump's other notable firings and resignations

Hicks, who was behind closed doors with the committee for more than nine hours, initially refused to answer any questions from investigators about the presidential transition or her time in the White House, with her lawyer telling the panel she was doing so under instructions from the White House.

It was only after Democrats tried to subpoena Hicks for her testimony on the spot, and it became clear that Hicks had discussed the transition in a recent interview with the Senate Intelligence Committee, that she and her legal team conferred with the White House and then answered "most" of the committee's questions about the transition, according to Rep. Adam Schiff, D-Calif., the top Democrat on the panel.

"This is a breathtakingly broad claim a privilege that I don't think any court would sustain, and I think the White House knows that. This is not executive privilege, this is executive stonewalling," he told reporters after the Hicks interview.

VIDEO: Top Dem says Hope Hicks refuses to answer questions about time in White House

One of the few White House staffers who has been at Trump's side since the early days of his campaign, Hicks faced questions about the campaign, transition and first year of the administration - including her role in the White House response to The New York Times report about Donald Trump Jr. and Jared Kushner's meeting with a Russian lawyer at Trump Tower in June 2016.

Hicks, who also has been interviewed by special counsel Robert Mueller's team, was "unwilling" to discuss the crafting of Donald Trump Jr.'s initial misleading statement about the meeting as she flew aboard Air Force One with President Trump, Schiff said.

Leaving Capitol Hill with her legal team Tuesday night, Hicks had no comment on her marathon session behind closed doors with congressional investigators.

She acknowledged to a House intelligence panel that she has occasionally told "white lies" for Trump. But she said she had not lied about anything relevant to the Russia investigation.

Hicks served as Trump's one-woman communications shop during his winning campaign and has remained one of his most trusted aides.

The Associated Press, ABC News' Matthew Mosk, Alexander Mallin and Jeff Cook contributed to this report.