Pope Francis and a leading Sunni imam have made calls for peace as the U.N. Security Council met to discuss the importance of "human fraternity" and condemn the hatreds that kindle conflicts.

The pope, who is in hospital recovering from abdominal surgery, sent a statement saying that a third world war is being fought "piecemeal" and with the potentially catastrophic effects of nuclear weapons "the time has come to say an emphatic 'no' to war."