VATICAN CITY - Pope Francis has paid a heartfelt tribute to his predecessor Benedict XVI, saying his faith and teaching had "enriched and invigorated" the Catholic Church and would remain its spiritual patrimony forever.

Francis offered the respects during an audience Friday with the cardinals who elected him to succeed Benedict, whose resignation set in motion the extraordinary conclave that brought the first prelate from the New World and first Jesuit to the papacy.

Speaking at times off the cuff, Francis said Benedict had "lit a flame in the depths of our hearts that will continue to burn because it is fueled by his prayers that will support the church on its missionary path."

Francis tripped when he greeted the dean of the College of Cardinals, Cardinal Angelo Scola, but he recovered immediately.