Pope Francis, comparing the current world situation to the Cuban missile crisis 60 years ago, on Tuesday led leaders of world religions in a peace appeal to politicians to avert the threat of nuclear war over Ukraine.
Francis presided at the ceremonial closing at Rome's Colosseum of a three-day conference organised by Italy's Sant' Egidio Community, a worldwide peace and charity group.
In his address to several thousand people, delivered after various religious groups prayed separately, Francis decried today's "bleak scenario, where, sad to say, the plans of potent world leaders make no allowance for the just aspirations of peoples".
Referring to the possibility of the use of nuclear weapons in Ukraine, Francis said: "Today, in fact, something we dreaded and hoped never to hear of again is threatened outright: the use of atomic weapons, which even after Hiroshima and Nagasaki continued wrongly to be produced and tested."
Francis recalled how on October, 25, 1962, at the height of the Cuban missile crisis, Pope John XXIII delivered a radio message appealing to leaders of the time to bring the world back from the brink.
"Today peace has been gravely violated, assaulted and trampled upon, and this in Europe, on the very continent that in the last century endured the horrors of two world wars," Francis said.
Sitting near the pope on the stage in front of the ancient Colosseum was Edith Bruck, 91, a Hungarian-born Holocaust survivor and author who lives in Italy.
"Sadly, since then, wars have continued to cause bloodshed and to impoverish the earth. Yet, the situation that we are presently experiencing is particularly dramatic," he said.
The closing ceremony was attended by Christians, Jews, Muslims, Sikhs, Buddhists and representatives of other religions.
The meeting's final appeal, read by a Syrian refugee, called for the banning of production of nuclear weapons.
The conference, most of which took place at a centre in Rome's outskirts, was opened on Sunday by French President Emmanuel Macron and Italian President Sergio Mattarella.
At the opening on Sunday, Macron said the Russian Orthodox Church, whose leader Patriarch Kirill is a ally of Russian President Vladimir Putin, was allowing itself to be manipulated by the country's authorities to justify their war in Ukraine and urged it to resist such pressure.