Calling him the "perfect choice" for secretary of state, President Barack Obama tapped U.S. Senator John Kerry to replace Hillary Clinton on Friday.

SOUNDBITE: U.S. President Barack Obama

"I think it's fair to say few individuals know as many presidents and prime ministers or grasps our foreign policy as firmly as John Kerry. And this makes him a perfect choice to guide American diplomacy in the years ahead."

Obama settled on the Massachusetts senator and 2004 Democratic presidential candidate - after the front-runner - U.N. Ambassador Susan Rice - took herself out of the running last week.

Several Republican lawmakers had said they would block a Rice nomination because of her role in the administration's early explanations about the attack on the U.S. consulate in Benghazi.

NAT SOUND: U.S. President Barack Obama

"He understands that we have a responsibility to use American power wisely."

On the cusp of his second term, Obama's choice of Kerry - marks the first step in overhauling his national security team.

SOUNDBITE: U.S. President Barack Obama

"As we turn the page on a decade of war, he understands that we have to harness all elements of American power."

Kerry - who chaired the Senate Foreign Relations Committee - is expected to be easily confirmed by his Senate colleagues.