Nikki Haley, U.S. ambassador to the United Nations, has resigned, with president Donald Trump accepting the resignation.

Iran Press/AmericaPresident Trump has accepted her resignation, but he tweeted that a "big announcement" was coming at 10:30 am on Tuesday morning. CBS News' Fin Gomez has confirmed the resignation. 

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 (website) first reported Haley's resignation.

Trump told reporters on Tuesday morning that Haley raised the possibility of taking a break six months ago, and that she's welcome back at any time. Some media reports have suggested that the reason for Haley's resignation was accepting bribes and accepting free flights. Other media reports have linked her resignation with her stance on the disappearance of famous Saudi Journalist Jamal Ahmad Khashoggi. Khashoggi disappeared after a visit to the Saudi consulate in Istanbul on 2 October.

Related news:

UN secretary general, Guterres "very concerned" about Saudi journalist's fate

Haley has charted her own course during the Trump administration, admitting in a recent op-ed that sometimes she disagrees with the president. Her op-ed was a response to an anonymous op-ed published in the New York Times from someone who identified as a senior administration official. Haley's op-ed was headlined, "When I challenge the president, I do it directly. My anonymous colleague should have, too."

"I, too, am a senior Trump administration official," Haley wrote in her op-ed. "I proudly serve in this administration, and I enthusiastically support most of its decisions and the direction it is taking the country. But I don't agree with the president on everything. When there is disagreement, there is a right way and a wrong way to address it. I pick up the phone and call him or meet with him in person."

Haley was an opponent of Trump's during the 2016 presidential race, and endorsed Senator Marco Rubio when she left the race. Since then, the two made amends — although, as Haley noted, she and the president were not always in lock-step agreement. 

Read more:

Haley denies Trump's lawyer claim over Iran's regime change

Infographic: The most notable firings and resignations in the Trump administration