Cathy Russell, director of the White House Presidential Personnel Office, is under consideration to serve as executive director of UNICEF, a position she has expressed interest in after it unexpectedly became open this month, according to two people with knowledge of the matter.

Russell, a longtime Biden aide who served as vice chair of his campaign, has significant influence in the White House and leads the office that is responsible for filling roughly 4,000 political appointment positions. She has expressed interest in the UNICEF job, and her stature within the administration is likely to make her a top candidate for the position, according to the two people, who spoke on the condition of anonymity to discuss personnel matters.

The White House declined to comment.

The secretary general of the United Nations appoints UNICEF’s director in consultation with the agency’s executive board. But as the United States is the largest funder of UNICEF, the position has always gone to an American.

UNICEF is responsible for providing humanitarian and development aid to children around the world, and the director oversees a multibillion-dollar budget with a presence in more than 190 countries and territories.

UNICEF chief Henrietta Fore announced her resignation this month, citing family health issues. Fore, who served as administrator of the U.S. Agency for International Development and as undersecretary of state for management during George W. Bush’s administration, took the job in January 2018 after being recommended by President Donald Trump.

Fore has said she will remain in the job until the conclusion of the U.N. General Assembly session in September and until her successor is chosen. The U.N. secretary general’s office and UNICEF declined to comment.

If Russell gets the job, she will probably be among the first senior staffers to depart the White House. Earlier this month, senior adviser Anita Dunn said she planned to leave “very shortly,” though she emphasized that her role was always intended to be a temporary one.

Russell has worked for Biden for decades, including on his 1988 presidential campaign. She also served as staff director on the Senate Judiciary Committee when Biden was chair and then worked for him again when he chaired the Senate Foreign Relations Committee.

Russell served as Jill Biden’s chief of staff when she was second lady and then became U.S. ambassador at large for global women’s issues during the second term of the Obama administration. She is married to Tom Donilon, who was President Barack Obama’s national security adviser, and her brother-in-law is Mike Donilon, one of Biden’s closest aides. Russell’s daughter works at the National Security Council.

As the head of the personnel office, Russell oversaw the confirmation process for members of Biden’s Cabinet, which the president has touted as being the most diverse in history. She has also spearheaded the selection of more than 200 nominees for Senate-confirmed roles.