WASHINGTON (AP) — White House press secretary Sarah Sanders will be leaving the Trump administration at the end of the month.

President Donald Trump announced the news on Twitter Wednesday. He says Sanders will be returning to her home state of Arkansas and has not immediately named a successor.

Sanders is one of the president’s closest and most trusted White House aides and one of the few remaining who worked on his campaign.

Her tenure was marked by a breakdown in regular White House press briefings and questions about the administration’s credibility.

Special counsel Robert Mueller’s revealed that Sanders admitted to investigators that she had made an unfounded claim that “countless” FBI agents had reached out to express support for Trump’s decision to fire FBI Director James Comey in May 2017.