In this photo provided by the Vatican paper L'Osservatore Romano, Pope Francis meets U.S. Vice President Joe Biden and his sister, Valerie Biden Owens, after his installation Mass at the Vatican on Tuesday, March 19, 2013. Pope Francis has urged princes, presidents, sheikhs and thousands of ordinary people gathered for his installation Mass to protect God's creation, the weakest and the poorest of the world. (AP Photo/L'Osservatore Romano)