White House Communications Director Hope Hicks, one of US President Donald Trump's most loyal aides, is resigning.
In a statement, the president praised Hicks for her work over the last three years. He said he "will miss having her by my side".
The news came 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.
She acknowledged to a House intelligence panel that she had 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.
She said in a statement, "There are no words to adequately express my gratitude to President Trump."