Haley threatened the pull-out a year ago, citing longstanding US complaints that the 47-member council is biased against Israel.
In remarks to the Graduate Institute of Geneva, given the same day as her council speech, Haley made the matter plain. She said that after repeated warnings by the Trump administration, "Regrettably, it is now clear that our call for reform was not heeded". It was the latest withdrawal by the Trump administration from an global institution.
In May, the U.S.
When the council was first established in 2006, the administration of George W. Bush withheld its membership over similar concerns. A year ago, she denigrated it as a "forum for politics, hypocrisy and evasion", and threatened a USA exit if the council did not kick out abusive regimes and remove Item 7, the standing resolution critical of Israel's treatment of Palestinians.
Last week, Reuters citing a source speaking on a condition of anonymity, reported that a United States withdrawal appeared to be "imminent".
UN Secretary-General Antonio Guterres regretted the USA decision, adding: "The UN's human rights architecture plays a very important role in the promotion and protection of human rights worldwide".
"The US's absence will only compound the council's weaknesses", they wrote.
"Human rights abusers continue to serve on and be elected to the council", Ambassador Haley explained.
British Foreign Secretary Boris Johnson on Monday urged the council to reform its treatment of Israel and assailed its controversial Agenda Item 7, which is dedicated to discussing rights abuses in the West Bank and Gaza Strip, according to the Times of Israel.
Whilst some European states and Australia have also criticised Item 7 in the past, the Trump administration has raised the prospect of the USA withdrawing from the council unless it is scrapped.
In a span of less than two months, USA officials have separated some 2,300 children from their parents after they crossed the border into the US, according to the Department of Homeland Security.
The withdrawal followed strong United Nations criticism of US President Donald Trump's policy to separate migrant children from their families at the US-Mexico border. The commission had faced severe criticism because its members included countries with poor rights records that undercut its mission.
But some questioned whether a US withdrawal will lead to reforms, or further undermine the council's mission.
"Its well-documented bias against Israel is unconscionable", Pompeo continued.
Reuters reported last week that activists and diplomats said talks with the United States on reforms had failed to meet Washington's demands, suggesting that the Trump administration would quit.
Both insisted the United States would remain a leading champion of human rights but, for many, the decision will reflect Trump's general hostility to the world body and to multilateral diplomacy in general.