(CBS) — Nikki Haley, U.S. ambassador to the United Nations, has resigned.

“She told me six months ago … at end of year, I want to take some time off,” President Trump said announcing Haley’s resignation—effective Dec. 31. “We hate to lose you. … You have done a fantastic job.”

“It has been an honor of a lifetime … to serve a country I love so very much,” Haley said. “Countries now respect what we do. … The U.S. is strong again.”  Haley did not disclose her plans after she leaves but ruled out a presidential run in 2020. “I look forward to supporting the president.”

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(Photo by Mark Goldman/Icon Sportswire via Getty Images)

President Trump has accepted her resignation, but he tweeted that a “big announcement” was coming at 10:30 a.m.

White House press secretary Sarah Sanders told pool reporters in a statement, “President Trump and Ambassador Nikki Haley will meet in the Oval Office at 10:30 a.m. this morning” in an event open to cameras and the press pool, meaning only a handful of journalists will be present.

Axios first reported Haley’s resignation.

This is a developing story and will be updated.