Pope Francis warned that the world is on the brink of a nuclear war like the 1962 Cuban missile crisis.

Francis conveyed the message at an international conference in Oslo commemorating the 60th anniversary of Pope John XXIII's influential encyclical Pacem in Terris on Tuesday.

In his message, according to Vatican News, he said the conference is taking place "as our world continues to be in the grip of a third world war fought piecemeal, and, in the tragic case of the conflict in Ukraine, not without the threat of recourse to nuclear weapons."

He drew a comparison between the present moment and the time of the Cuban missile crisis in October 1962 when the world was perilously close to nuclear destruction.

Urging the conference to focus on the sections of Pacem in Terris that address disarmament and the ways to achieve long-lasting peace, the pontiff said that "a world free of nuclear arms is possible and necessary."

He also recalled his statement from the Hiroshima Peace Memorial in 2019, when he said that "the use of atomic energy for purposes of war is immoral, just as the possessing of nuclear weapons is immoral."

Regarding conventional arms, he said that they "should be used for defensive purposes only and not directed to civilian targets."