Elena Kagan sworn in as 112th US Supreme Court justice [VIDEO]

Kagan pledged to "faithfully and impartially" administer justice to people from all walks to life as she took the judicial oath from Chief Justice John Roberts.

She also promised to "work my hardest and try my best to fulfill these commitments and serve this country I love."

"Welcome to the court," Roberts told Kagan, as the newest justice grinned broadly for the cameras.

Supreme Court Justices Anthony Kennedy, Ruth Bader Ginsberg, Sonia Sotomayor and Clarence Thomas -- whom Kagan will join on the bench for the first time October 1 for the court's fall session -- were present at the ceremony, along with Justice John Paul Stevens, whom Kagan replaces.

Kagan took two oaths, the first in a private ceremony with Roberts and her family, and a second one for the public.

The senate voted 63-37 Thursday to confirm Kagan as one of the nine justices who act as final arbiters of the US constitution, set precedent for lower courts, and decide on the toughest moral and legal dilemmas facing the United States.