President Donald Trump's ambassador to the United Nations Nikki Haley told reporters Tuesday she will not make a White House run in 2020, saying she will campaign for Trump's re-election.

Trump and Haley appeared together in the Oval Office on Tuesday to confirm reports of Haley's surprising resignation from her post. She will officially leave at the end of the year.

Haley, one of the most popular figures in the Trump administration, got ahead of questions about her political future by telling the press she would not seek the presidency in 2020.

"For all of you that are going to ask about 2020, no, I am not running [in] 2020. I can promise you what I'll be doing is campaigning for this one," she said, pointing at Trump. "So I look forward to supporting the president in the next election."

"That's so good," Trump said, smiling.

Trump offered warm words for her tenure, saying she had been "very special" to him and done a "fantastic job." Haley thanked Trump for giving her the position and praised him in turn, saying the country was "respected" again in the world.

Haley's tenure was marked by strong defense of Israel against bias at the U.N., leadership on the global sanctions regime against North Korea, and a stern condemnation of Russian malfeasance in Syria.

Haley said she had no "personal reasons" for resigning and hinted she was not exiting politics for good, saying she would "never truly step aside from fighting for our country." Haley spent six years as South Carolina Governor before heading to the U.N.

"I have given everything I've got these last eight years, and I do think that sometimes it's good to rotate in other people who can put that same energy and power into it," she said. "The truth is I want to make sure this administration, the president has the strongest person to fight. It was a blessing to go into the U.N. with body armor every day and defend America, and I'll always do that. I'll never truly step aside from fighting for our country. But I will tell you that I think it's time."

Haley spoke out against Trump during the Republican primary in 2016 and endorsed his opponent Sen. Marco Rubio (R., Fla.). His offering to her of the U.N. post was widely seen as an olive branch to the GOP establishment.