Updated 4:55 p.m. ET
Nikki Haley is resigning as the U.S. ambassador to the United Nations and will leave the Trump administration at the end of the year, she said Tuesday.
It is not immediately clear what prompted the move. She informed her staff Tuesday, NPR's Michele Kelemen reports.
Haley appeared with President Trump on Tuesday morning at the Oval Office, where he called her a "fantastic person" and said Haley had told him six months ago that she might take time off at the end of the year.