Susan Rice will replace Tom Donilon as President Barack Obama's national security adviser an anonymous public official told The Associated Press.
Donilon is known for his contributions in pivoting US foreign policy toward Asia and was a staunch defender of the drone program.
He was said to have enormous influence on the president but had a tense relationship with other White House staffers.
Rice currently serves as the US ambassador to the United Nations in New York.
An anonymous White House official told the AP that Rice will be replaced by long-term Obama adviser Samantha Power.
Power's appointment will be announced later on Wednesday.
Politico pointed out that the appointment of both women shows that the administration is making human rights a priority, particularly during a time of violent unrest in the Middle East.
Power rose to prominence because of her book, "A Problem from Hell," which chronicles America's failure to prevent genocide around the world.
Rice has been sharply criticized in recent months for her handling of the Benghazi incident last September in which Ambassador J. Christopher Stevens and three other Americans were killed.
The national security adviser does not require Senate approval to be confirmed.