In a long-awaited speech in Nagasaki, Pope Francis on Sunday strongly criticized the concept of nuclear deterrence and warned of arms races while calling on world leaders to instead use money and resources to cope with environmental issues and poverty that affect millions of people worldwide who are "living in inhumane conditions."

"Peace and international stability are incompatible with attempts to build upon the fear of mutual destruction or the threat of total annihilation," the pope told scores of people who had gathered to hear him speak amid a light rain at the Atomic Bomb Hypocenter Park, ground zero of the second of the two atomic bombs that were dropped on Japan by the United States in 1945.

"In a world where millions of children and families live in inhumane conditions, the money that is squandered and the fortunes made through the manufacture, upgrading, maintenance and sale of ever more destruction weapons, are an affront crying out to heaven," the pope said.