VATICAN CITY (CNS) — The scars still borne by survivors of the atomic bombings of Hiroshima and Nagasaki and still visible on the cities’ streets and buildings are a plea to pursue peace and disarmament, Pope Leo XIV said.

“True peace demands the courageous laying down of weapons — especially those with the power to cause an indescribable catastrophe,” the Pope wrote in a message to Bishop Alexis Mitsuru Shirahama of Hiroshima.

“Nuclear arms offend our shared humanity and also betray the dignity of creation, whose harmony we are called to safeguard,” he wrote in the message released at the Vatican on August 5.

The Pope’s message was sent as people gathered from around the world to solemnly mark the 80th anniversary of the U.S. bombing of Hiroshima on August 6, 1945, and Nagasaki on August 9, 1945.

Pope Leo also marked the anniversary on August 6 at the end of his weekly general audience with thousands of people gathered in St. Peter’s Square.

“Despite the passing of the years, those tragic events remain a universal warning against the devastation caused by wars, and in particular by nuclear weapons,” the Pope said. “I hope that in today’s world the illusory security based on the threat of mutual destruction will give way to the tools of justice, the practice of dialogue and trust in fraternity.”

The bombings killed more than 150,000 people, mostly civilians, and left the cities in ruins.

In his message to Bishop Shirahama, Pope Leo conveyed “sentiments of respect and affection for the ‘hibakusha'” or survivors of the bombings, “whose stories of loss and suffering are a timely summons to all of us to build a safer world and foster a climate of peace.”

The Pope noted how even after 80 years, “the two cities remain living reminders of the profound horrors wrought by nuclear weapons. Their streets, schools, and homes still bear scars — both visible and spiritual — from that fateful August of 1945.”

“In this context,” he said, “I hasten to reiterate the words so often used by my beloved predecessor Pope Francis: ‘War is always a defeat for humanity.'”

Today, at a time of “mounting global tensions and conflicts,” he wrote, Hiroshima and Nagasaki are signs “that urge us to reject the illusion of security founded on mutually assured destruction. Instead, we must forge a global ethic rooted in justice, fraternity, and the common good.”

Pope Leo prayed that the 80th anniversary of the bombings would “serve as a call to the international community to renew its commitment to pursuing lasting peace for our whole human family — ‘a peace that is unarmed and disarming,'” he said, quoting a phrase he used when addressing the crowd in St. Peter’s Square immediately after his election May 8.