Washington: Leon Panetta has taken charge as the new Defence Secretary of the United States while Robert Gates has retired from his position as Defence Secrertary .
Robert Gates has left office according to new changes while Leon Panetta has taken oath of his new assignment.
Chief of US-led forces in Afghanistan General Petraeus has also taken oath as CIA Chief after approval of the US Senate.
Leon Panetta vowed that he would take measures to make the US army powerful military in the world.
Robert Gates retires; Panetta takes over charge as US Defence Secretary ,
