Nikki Haley is resigning from her post as United States ambassador to the United Nations effective at the end of 2018, with President Donald Trump indicating he had advance warning she would leave.

“Big announcement with my friend Ambassador Nikki Haley in the Oval Office at 10:30am,” Trump wrote on Twitter ahead of their Tuesday morning meeting.

Trump said at the meeting with reporters present that Haley had told him months ago she intended to serve for less than two years.

Haley, who has been one of Trump’s most trusted advisers, would not confirm the report to Reuters when asked about it on her arrival at the White House today.

The move will raise speculation about her political future.

Haley, 46, served as South Carolina’s governor from 2011 until she was nominated by Trump to the UN post, a move that surprised some observers given her lack of foreign policy experience.

She was the first governor in the U.S. of Asian descent, her parents having been born in India.

Haley’s replacement will require confirmation by the Senate, with over two-thirds of the seats in that legislative body being contested in next month’s midterm elections. Haley was confirmed with 96 of 100 votes.

With files from Reuters