With Haley sitting at his side, Trump told a crowd of reporters that she will be leaving at the end of the year, explaining that her job as ambassador allowed her to get to know numerous other global players and world leaders. In a rare move President Trump invited reporters to speak with him and Haley on her resignation in the Oval Office.
But the Post's John Hudson speculates Haley's opposition also could've driven her departure.
Like President Trump, she has an eye for a television moment, and after the Assad regime launched a chemical weapons strike in April 2017, she brandished pictures of dead children in the Security Council.
US President Donald Trump, who met Haley in the Oval Office on October 9, accepted the resignation. She will leave at the end of the year, he said.
"Thank you Mr President; it's been an honour of a lifetime", she told Trump.
In April, she clashed with the White House when a Trump aide suggested she had prematurely announced a new round of sanctions against Russian Federation.
Echoing previous statements from Trump, Haley said the United States under his presidency is now respected around the world.More news: Chelsea legend John Terry announces retirement from football
At the UN, Haley helped spearhead the Trump administration's efforts to combat what it alleged to be anti-American and anti-Israel actions by the worldwide body.
"I don't see (my role) as pushing an "America First" policy, I see it as defending America because every day I feel like I put body armor on".
In her brief White House press conference with President Trump, Haley said it was her "honor" to have defended America. It came in response to an anonymous essay in The New York Times by a senior administration official that alleged there to be a secret "resistance" effort from the right in Trump's administration and that there were internal discussions of invoking the 25th amendment to remove him from office.
There has been frequent speculation that Haley harbours her own presidential ambitions, however she has repeatedly insisted that she was focused on the job at hand, not future opportunities.
"I will support the president", Haley said.
'They do a lot of things behind the scenes that I wish more people knew about because we are a better country because they're in the administration'. She was re-elected in 2014. Elected as the state's first female governor in 2010, she was in her second four-year term when Trump picked her.
Following Swan's report, Fox News and CNN confirmed Haley's resignation.