The news blindsided many congressional Republicans involved in foreign policy matters and some key USA allies.
As it turned out, Haley suggested her departure was no more than a case of burnout.
"I've heard a lot of names".
When asked about her reasons for resigning from her position, Haley said it's important for government officials to recognize when it is the right time to step aside.
Haley achieved a rare feat in the Trump administration, maintaining her personal popularity despite the president's polarizing politics.
Many describe Haley as a fierce presence on the Security Council.
"This is an appropriate way of doing it", Trump said, calling Haley a "very special" person.
Instead of answering directly, he recounted how she has had to work on tough issues, such as Iran and North Korea. Several senior White House aides wondered about the timing of her decision, weeks before midterm congressional elections.
That, in turn, prompted speculation that maybe Haley was angling after the vice president job instead.
As ambassador, Haley was an outspoken and often forceful envoy - someone whom foreign diplomats looked to for guidance from an administration known for haphazard and inconsistent policy positions. ".I can speak for Secretary of State Mike Pompeo".
Haley reported earning $9,759 as governor in 2017, before she resigned in January to join the Trump administration, as well as a bank account with between $1,000 and $15,000 in it. He insisted later that the delegates were laughing with him, not at him.
"I'm not leaving until the end of the year". Trump added that Haley told him she wanted a break around six months ago.
Haley, a rookie to worldwide politics, was an unusual pick for to be United Nations envoy.
Former S.C. Gov. Nikki Haley will leave her post at the United Nations with a burnished national reputation. "Countries may not like what we do but they respect what we do...nations get that the President means business", she said.
Haley, the former governor of SC, was a critic of Trump's during the 2016 Republican primaries and endorsed his opponent Sen. She was re-elected in 2014.