President-elect Donald Trump choice for United Nations ambassador, South Carolina Gov. Nikki Haley, has limited foreign policy experience. That's in contrast to other U.N. ambassadors who had deep roots in international affairs at the time of their nominations.

A look at the backgrounds of the four most recent U.S. ambassadors to the United Nations:

— Samantha Power (2013-present): A Pulitzer Prize-winning journalist for her examination of America's historical responses to genocide, Power was born in Ireland and came to the United States as a child. She worked for then-Sen. Barack Obama and then for his presidential campaign as a foreign policy adviser. During Obama's first term, she served in his National Security Council. There, she joined an influential group of advisers who pushed for the U.S.-led bombing campaign in Libya.

— Susan Rice (2009-2013): A Rhodes scholar who studied international relations at Oxford, Rice was a foreign policy wonk from a young age. She served as an adviser to Democratic presidential candidate Michael Dukakis during the 1988 campaign and to Bill Clinton four years later. Under Clinton, she worked in the National Security Council and then as assistant secretary of state for African affairs. After advising Obama's 2008 campaign, she joined his Cabinet after the newly inaugurated president elevated the position of U.N. ambassador.

— Zalmay Khalilzad (2007-2009): A native of Afghanistan, Khalilzad was educated at the American University in Beirut and the University of Chicago. A speaker of four languages, he served in senior national security positions during the presidencies of Ronald Reagan and George H.W. Bush. President George W. Bush tapped him to be his Afghanistan envoy after the Sept. 11, 2001, terrorist attacks. He then served as ambassador to Afghanistan during its critical, post-Taliban period of drafting a constitution and setting up a new government, and worked closely with then-Afghan President Hamid Karzai. Bush then sent him as ambassador to Iraq during the height of sectarian violence following the U.S. invasion.

— John Bolton (2005-2006): Bolton was probably the most divisive foreign policy expert ever to serve as U.N. ambassador. Born in Baltimore, he graduated summa cum laude from Yale before serving at three federal agencies under Presidents Ronald Reagan and George H.W. Bush. When George W. Bush became president, Bolton served as the State Department's point-man on arms control, where he battled other governments on nuclear weapons tests, land mines, biological weapons, balllistic missile limits and the International Criminal Court. An unabashed proponent of American power and a strong supporter of the Iraq war, Bolton was unable to win Senate confirmation after his nomination to the U.N. post turned off many Democrats and even some Republicans. He resigned after serving 17 months as a Bush "recess appointment," which allowed him to hold the job on a temporary basis without Senate confirmation.