In the United States, the permanent representative to the United Nations is nominated by the president and confirmed by the Senate. Candidates must be vetted before landing on a list of potential nominees, a process that can take several weeks or months. Ambassadors from the United States, after nomination by the president, must answer questions in front of senators as to why they are qualified for the post.
Ambassador Samantha Power, the current ambassador to the U.N. from the United States, served on President Barack Obama's staff as senior director for multilateral affairs and human rights. Previous to her public service, Power worked for Harvard University's John F. Kennedy School of Government as a professor who taught courses on human rights, foreign policy and U.N. reform. Power holds an undergraduate degree from Yale University and a law degree from Harvard.
People, most notably celebrities or well-known sports figures, can become Goodwill Ambassadors representing the United Nations at various charitable work sites in developing countries. Mia Farrow, Serena Williams, Danny Glover, Whoopi Goldberg and Katy Perry are UNICEF ambassadors from the United States who tout UNICEF's programs throughout the world. These ambassadors do not officially represent a country but rather uplift local residents that need U.N. programs.