White House Communications Director Hope Hicks, President Donald Trump's longest-serving aide, announced her resignation on Wednesday.

Hicks, 29, has been a longtime member of the Trump family's inner circle, having served as press secretary for his presidential campaign before being tapped to join the White House staff. Hicks, a former model, previously worked for the Trump Organization and for Ivanka Trump's fashion brand.

Her resignation, first reported by The New York Times, comes a day after she appeared before the House Intelligence Committee, which is investigating Russian interference in the 2016 election, and acknowledged that she sometimes tells "white lies" for the president, according to lawmakers.

Her exact departure date is to be determined, but it will be sometime in the next few weeks. Officials said she wanted to pursue new opportunities outside the White House.

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In a statement, Hicks thanked the president for his "gratitude." According to a White House officials, she informed him of her decision to resign earlier today, in person.

Trump also issued a statement praising Hicks for her service.

"Hope is outstanding and has done great work for the last three years. She is as smart and thoughtful as they come, a truly great person," the president said. "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."

White House officials told NBC News that Hicks was considering leaving prior to the domestic abuse scandal involving former White House staffer Rob Porter, who resigned earlier this month. Hicks spoke with communications and press teams today about her departure in two groups: first a smaller one, then a larger one, both in the press secretary's office, a source with direct knowledge of the meetings said. This person described the meetings as "pretty emotional" with "lots of tears and hugs," but Hicks didn’t give the group a specific reason for her departure during the meetings.

One source close to the White House told NBC News that "it won't be the same" without Hicks in the administration, underscoring how enduring a presence she was in Trump's world — as well as an administration that has been roiled by departures in its first year.

Ivanka Trump, the president's daughter and a senior adviser, tweeted well wishes to Hicks, saying she was "loved & admired."

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 — Ivanka Trump (@IvankaTrump) February 28, 2018

Hicks, who has served as a key aide to Trump since the real estate mogul launched his presidential bid in June 2015, began her White House tenure as director of strategic communications. She was tapped as interim communications director after Anthony Scaramucci was fired in July after just 10 days on the job, a role that was made official in September 2017. The promotion made her Trump's fourth communications director over the course of his first year in office.

White House Press Secretary Sarah Huckabee Sanders told NBC News on Wednesday that Hicks’ departure had "nothing to do with yesterday,” referring to her testimony before the House panel investigating Russian interference. Sanders said that Hicks’ departure had been in the works for "several weeks" and "didn't happen overnight."

During her closed-door testimony with House investigators on Tuesday, Hicks declined to answer questions about her time in Trump's administration, saying that White House had advised her not to answer.

Hicks, an important eyewitness to campaign and White House matters potentially relevant to the ongoing government probes into Russian meddling, also declined to answer most questions about the transition period between Election Day and Inauguration Day. Lawmakers said she started to answer some questions from that time.

Sanders added Wednesday that Hicks' desire to spend more time with family also factored into her decision, and that Trump is "not unhappy with her in any capacity."