Pope Francis on Sunday said at an event in Nagasaki, Japan that the world must stop spending resources on nuclear weapons, calling funding the arms race in the face of humanity's problems of poverty, the climate, and other issues "an affront crying out to heaven."

"The arms race wastes precious resources that could be better used to benefit the integral development of peoples and to protect the natural environment," the Pope said.

The speech came on the second day of the first papal visit to Japan since 1981 and was part of the pontiff's tour of Hiroshima and Nagasaki, the two Japanese cities bombed by the U.S. at the end of World War Two.

"This place makes us deeply aware of the pain and horror that we human beings are capable of inflicting upon one another," Pope Francis said.

The Pope spoke in front of a photograph from the bombing showing a young boy walking with the corpse of his younger brother strapped to his back, taking the body to a crematorium after the blast. As The Guardian reported, Pope Francis was first given a copy of the photo a few years ago and has since distributed copies around the world to show the cost of nuclear war.

The Catholic Church has long been opposed to the use and proliferation of nuclear weapons.

According to The Guardian:

The 82-year-old pontiff, who will visit Hiroshima later Sunday, has long been a vocal opponent of nuclear weapons. The Holy See was among the first countries to sign and ratify a 2017 nuclear prohibition treaty. But nuclear powers, and countries such as Japan that fall under the US nuclear umbrella, have refused to sign it.

The Pope's comments came a month after Catholic anti-nuclear activists were found guilty of an action against proliferation and war in Georgia. The Kings Bay Plowshares Seven took action, they said, to stop the threat of global annihilation.

"We resist militarism that has employed deadly violence to enforce global domination," the group said in their mission statement.

Reporter Sam Husseini, writing for Common Dreams, said the Georgia Plowshares group and the Pope have the same message. Francis "is expected to give the clearest articulation yet of the Vatican's position, since 2017, that condemns the 'very possession' of nuclear weapons," wrote Husseini. "This is something Plowshares activists have been arguing—and acting upon—since 1980."

The Pope, in Japan, sounded a similar note.

"One of the deepest longings of the human heart is for security, peace, and stability," said Francis. "The possession of nuclear and other weapons of mass destruction is not the answer to this desire—indeed, they seem always to thwart it."