"I'm pleased that the Senate has confirmed Samantha Power as our next U.S. ambassador to the United Nations by a strong, bipartisan majority," President Barack Obama said in a statement.
"As one of our country's leading foreign policy thinkers, Samantha knows that our nation's interests are advanced with strong and principled American leadership. As a longtime champion of human rights and dignity, she will be a fierce advocate for universal rights, fundamental freedoms and U.S. national interests.
"I'm grateful that Samantha will continue to be a vital member of my national security team, and I know that under her leadership our U.N. Mission in New York will continue to represent American diplomacy at its best," Obama said.
Power was an early proponent of U.S. intervention in Libya when she served on Obama's first-term national security team. She replaces Susan Rice, who last month took over from Tom Donilon as Obama's national security adviser.