In a message to an international gathering on the impact of nuclear weapons, Pope Francis called on victims to be "prophetic voices" against the potential for destruction of persons and the planet.

These victims, he said, "warn us not to commit the same irreparable mistakes which have devastated populations and creation."

The Pope's letter was addressed to Sebastian Kurz, Austrian foreign minister and leader of a two-day conference on the "Humanitarian Impact of Nuclear Weapons."

Among those present at the gathering were victims – known as the Hibakusha – of the atomic bombings of the Japanese cities of Hiroshima and Nagasaki by U.S. forces during World War II.

Pope Francis encouraged these and other victims represented at the conference, "to be prophetic voices, calling the human family to a deeper appreciation of beauty, love, cooperation and fraternity, while reminding the world of the risks of nuclear weapons which have the potential to destroy us and civilization."

The conference, held in Vienna from Dec. 8-9, was attended by high-ranking officials from 158 countries and civil society organizations.

In his message, dated Dec. 7, Pope Francis cited nuclear weapons as a "global problem," impacting "future generations" as well as the planet.

"A global ethic is needed if we are to reduce the nuclear threat and work towards nuclear disarmament," he said.

People need to be encouraged "to work together for a more secure world, and a future that is increasingly rooted in moral values and responsibility on a global scale."

In addition to recognize their "potential for mass-killing," the Holy Father called for greater attention to the "unnecessary suffering" which results from the use of nuclear weapons.

"Nuclear deterrence and the threat of mutually assured destruction," he said, "cannot be the basis for an ethics of fraternity and peaceful coexistence among peoples and states."

Young people, now and in the future, "deserve a peaceful world order based on the unity of the
human family, grounded on respect, cooperation, solidarity and compassion."

The Holy Father stressed that "the logic of fear" must be countered with "the ethic of responsibility," thereby fostering "a climate of trust and sincere dialogue."

Pope Francis condemned squandering "the wealth of nations" on nuclear weapons, stressing that  spending should instead be directed toward "integral human development, education, health and the fight against extreme poverty."

"When these resources are squandered, the poor and the weak living on the margins of society pay the price," he said.

"The desire for peace, security and stability is one of the deepest longings of the human heart," he said, "rooted in the Creator who makes all people members of the one human family."  Neither military means alone, nor "the possession of nuclear weapons" can satisfy this desire.

Rather, "peace must be built on justice, socio-economic development, freedom, respect for fundamental human rights, the participation of all in public affairs and the building of trust between peoples."

Pope Francis encourage participants in the conference toward "sincere and open dialogue between parties internal to each nuclear state, between various nuclear states, and between nuclear states and non-nuclear states."

"This dialogue must be inclusive, involving international organizations, religious communities and civil society, and oriented towards the common good and not the protection of vested interests."

"I am convinced that the desire for peace and fraternity planted deep in the human heart will bear fruit in concrete ways to ensure that nuclear weapons are banned once and for all, to the benefit of our common home," he added.

"The security of our own future depends on guaranteeing the peaceful security of others, for if peace, security and stability are not established globally, they will not be enjoyed at all.

Pope Francis concluded his message by stressing the individual and collective responsibility to care "for the present and future well-being of our brothers and sisters."

"It is my great hope that this responsibility will inform our efforts in favor of nuclear disarmament, for a world without nuclear weapons is truly possible."