President Barack Obama will name a former aide and genocide expert Samantha Power as the new US ambassador to the United Nations, to replace Susan Rice, who will take over the top slot of his national security advisor.
Obama will make the announcement at the White House, as he names Rice to take over from his current national security advisor Tom Donilon, who is leaving next month, the official said.
Obama plans to make the appointment, which is seen as a major change in his foreign policy, later on Wednesday.
Rice’s appointment as Obama’s top security adviser does not require Senate confirmation.
Obama had wanted to name Rice as his secretary of state, but she ran into heavy opposition from Republicans over remarks she made in the aftermath of the September 11, 2012 attack on the US mission in Benghazi, Libya, that killed four Americans, including Ambassador Christopher Stevens.
Rice, a close confidante of Obama, withdrew her name from consideration for the top diplomatic post in December.
Donilon, who served for more than four years as Obama’s top national security adviser, will leave in early July, a White House official said.
The shake-up comes as the Obama administration struggles with its response to the civil war in Syria.