A White House official says President Joe Biden will nominate a longtime aide to represent the United States at the United Nations agency devoted to education, science and culture. The official says Courtney O'Donnell is Biden's choice to become the U.S. permanent representative to the Paris-based U.N. Educational, Scientific and Cultural Organization, or UNESCO. O'Donnell would have the rank of ambassador. O'Donnell is a longtime Biden aide. She currently is a senior adviser to Vice President Kamala Harris and acting chief of staff for Harris' husband, Doug Emhoff. The U.S. recently rejoined UNESCO after a five-year absence.