US President-elect Donald Trump has picked South Carolina Governor Nikki Haley, who was critical of him during his election campaign and who has little foreign policy experience, to be US ambassador to the United Nations.

The choice of Ms Haley was announced in a statement on Wednesday (local time) from Mr Trump’s transition team.

“Governor Haley has a proven track record of bringing people together regardless of background or party affiliation to move critical policies forward for the betterment of her state and our country,” the statement said.

Ms Haley, a 44-year-old Republican, sharply criticised Mr Trump during the presidential campaign over his harsh rhetoric about illegal immigrants and for not speaking forcefully enough against white supremacists.

The choice of Ms Haley — a daughter of Indian immigrants and an active voice for tolerance — could be aimed at countering criticism of Mr Trump’s divisive comments about immigrants and minorities, as well as accusations of sexism during his election campaign.

Ms Haley led an effort last year to remove the Confederate flag from the grounds of the South Carolina state capitol after the killing of nine black churchgoers in Charleston.

The flag was carried by pro-slavery Confederate forces during the US Civil War and is viewed by many as a racist emblem.

She condemned Mr Trump during the Republican presidential primary campaign for not disavowing the support of white supremacist group Ku Klux Klan and one of its former leaders, David Duke.

In her rebuttal to President Barack Obama’s State of the Union address in January, Ms Haley called for tolerance on immigration and civility in politics in what some saw as a rebuke of Mr Trump.

“During anxious times, it can be tempting to follow the siren call of the angriest voices,” she said.

“We must resist that temptation.”

In the early days of the primary contest to pick this year’s Republican presidential nominee primary, Ms Haley was mentioned as a possible vice-presidential pick.

She supported Mr Trump’s rivals Marco Rubio and Ted Cruz, both US senators, in the primary before saying last month she would vote for Mr Trump despite reservations about his character.

Mr Trump is due to succeed Mr Obama on January 20.

Ms Haley also criticised Mr Trump for not releasing his tax returns, prompting the New York real estate mogul to hit back on Twitter, saying: “The people of South Carolina are embarrassed of Nikki Haley!”

Little foreign experience for next UN ambassador

Ms Haley was a state politician before becoming governor and has little experience in foreign relations.

According to the Post and Courier of Charleston, her international experience involves negotiating development deals with international companies who want to work in South Carolina. She has led seven overseas trade missions as Governor, it reported.

“She is also a proven dealmaker, and we look to be making plenty of deals. She will be a great leader representing us on the world stage,” the statement announcing her appointment said.

Ms Haley’s husband, Michael, was deployed for almost a year in Afghanistan with the South Carolina National Guard in 2013, said the Post and Courier, which first reported Ms Haley had been picked for the job.

She will succeed Mr Obama’s UN envoy, Samantha Power, in the high-profile position.

The United States is one of five permanent veto-powers on the 15-member UN Security Council, along with Russia, China, France and Britain.

Ms Haley will be working with a new UN secretary-general after the United Nations General Assembly appointed former Portuguese prime minister Antonio Guterres in October for a five-year term beginning January 1, 2017.

He will replace Ban Ki-moon of South Korea.

Washington is the largest funder of the 193-member United Nations, paying more than a quarter of the $US8 billion peacekeeping budget and 22 per cent of the several-billion-dollar regular budget.

Reuters