The Pope has said laughing at God is "not blasphemy" but cautioned that humour "does not offend" in a landmark address to comedians and celebrities today.

Speaking at the Vatican to an audience which included hit US stars like Whoopi Goldberg, Jimmy Fallon, Conan O'Brien, Chris Rock and Stephen Colbert, Pope Francis made the remarks in an address billed as a warm-up to his later meeting with Joe Biden at the G7 conference in Italy.