President Joe Biden will nominate a longtime aide who once worked for the first lady to represent the United States at the United Nations agency devoted to education, science and culture, a White House official said Monday.

The U.S. recently rejoined the U.N. Educational, Scientific and Cultural Organization after a five-year hiatus initiated by Biden’s immediate predecessor in the White House, Donald Trump.

The Democratic president’s choice to become the U.S. permanent representative to the Paris-based UNESCO, with the rank of ambassador, is longtime aide Courtney O’Donnell, according to the official, who spoke on the condition of anonymity to discuss the nomination before a formal announcement.

O’Donnell currently wears two hats in the administration: She’s a senior adviser in Harris’ office and acting chief of staff for Harris’ husband, second gentleman Doug Emhoff, and lends her expertise to a range of national and global issues, including gender equity and countering antisemitism, a top issue for Emhoff, who is Jewish.