The White House confirmed news of Hicks’ departure on Wednesday, one day after Hicks testified before the House intelligence committee for nine hours as part of the panel’s investigation into Russian interference in the 2016 presidential election.

“There are no words to adequately express my gratitude to President Trump,” Hicks said in a statement. “I wish the President and his administration the very best as he continues to lead our country.”

Hicks had served as the press secretary for Trump’s insurgent presidential campaign before taking on similar duties in the White House. She previously worked at the Trump Organization and went on to become Trump’s longest-serving political aide.

“Hope is outstanding and has done great work for the last three years,” Trump said in a statement. 

“She is as smart and thoughtful as they come, a truly great person. I will miss having her by my side but when she approached me about pursuing other opportunities, I totally understood. I am sure we will work together again in the future.”

The White House said Hicks’ exact departure date had yet to be determined, but that she would leave in the coming weeks. 

Hicks, 29, a former model, had no political experience when she joined Trump’s tumultuous campaign for the White House. She quickly rose as one of his closest confidantes, ranking among the few aides to develop an understanding of Trump’s brash persona and unpredictable temperament.

Hicks initially served as a press secretary within the White House, before taking on the role of communications director following a series of high-profile departures last year.

In that role, Hicks was tasked with bringing stability to Trump’s unruly press shop, which in its early stages was dominated by leaks and constant reports of infighting.

Although Hicks maintained an unusually low profile over the past three years, she recently attracted more scrutiny in her role, as special counsel Robert Mueller escalated his investigation into potential collusion between the Trump campaign and Moscow.

Hicks’ proximity to the president, and presence on his campaign from its infancy, placed her in the spotlight as a potentially key witness to the FBI’s inquiry.

Questions loomed in particular over her role in crafting a highly misleading statement about the infamous June 2016 meeting at Trump Tower between Donald Trump Jr, Jared Kushner, Paul Manafort and Russian lawyer Natalia Veselnitskaya.

The White House at first said the meeting was to discuss adoptions, but it was later revealed that the meeting had been arranged when the Russians offered to provide Trump Jr with highly sensitive and incriminating information about Hillary Clinton.

Hicks allegedly promised that Trump Jr’s emails with the Russians “will never get out”. A lawyer for Hicks denied the claim. Trump Jr was forced to release the emails after reports uncovered the true nature of the meeting.

Hicks told congressional investigators on Tuesday she occasionally had to tell white lies to appease Trump, but denied having lied about substantive matters pertaining to Russia.

Hicks was also interviewed in December by the special counsel’s team, which has zeroed in both on the White House response to the 2016 Trump Tower meeting and Trump’s firing of the former FBI director James Comey.

Hicks also became engulfed in the scandal involving Rob Porter, who served as Trump’s staff secretary until he was forced to resign this month amid accusations of domestic violence by both of his ex-wives. Hicks had been dating Porter, but the two reportedly split following the controversy.

Ivanka Trump, the president’s daughter and aide, tweeted on Wednesday evening: “Hope Hicks is loved & admired by all who know her. It’s with a heavy heart, but tremendous gratitude, that I wish her well in her next steps.”

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