While their message is a general appeal, it would seem to be addressed to the administration of President Trump, which has taken the decision to withdraw from the Paris climate accord.

In an extended interview, the pope shares hitherto unknown aspects of his personal life and his vision of the world.

Pope Francis "trusts that the immense and immediate needs of so many individuals and communities will continue to inspire a vast outpouring of solidarity and mutual aid in the best traditions of the nation."

The forthcoming joint message will ask people of all faiths "to adopt a respectful and responsible approach toward creation."

Throughout the Gospels, Jesus is like an "arsonist," the pope said, setting people's hearts ablaze.