US Senate on Thursday confirmed Ash Carter to be the new chief to run the Pentagon.

The vote for the appointment of President Barack Obama's choice cleared the Senate floor easily with 93 to 5. Ash Carter will replace Chuck Hagel and be Obama's fourth defense secretary in six years.

Carter will take the helm at US Department of Defense as Washington is bogged down in several complicated national security challenges across the globe.

One of the challenges was Obama's effort to urge the Congress to pass a fresh war power authorization against the extremist group Islamic State, which had been criticized by both parties in Congress.