(CNN) -- Pope Francis said Saturday he worries that rising tensions between the United States and North Korea could lead to a wide military conflict that would wipe out a "large part of humanity."
He called for renewed diplomacy using third-party intermediaries and for the United Nations to take a lead role in de-escalating tensions.
The Pope, while returning to Italy from Egypt, took several questions from reporters and one asked him what he would say to world leaders at this critical moment.
Francis said in Italian that the situation "has heated up too much. I always appeal for a solution through diplomatic means."
The pontiff, who has spoken of a "piecemeal third world war" for several years, said increased conflict would be devastating.
"It's piecemeal but the pieces are getting larger, and are concentrated in places which were already hot," Pope Francis said. "Today a wider war would destroy, I won't say half of humanity, but a large part of humanity and culture. It would be terrible. I don't think humanity today could bear it."
Diplomacy is the best response in these times, he said.
"I think the United Nations has the duty to resume its leadership, because it has been watered down a bit," he added.
He suggested using a nation like Norway to facilitate talks between Pyongyang and Washington, but said there are many that could fill the role. (The United States uses Sweden to represent its diplomatic interests in North Korea.)
The Pope was returning from a trip designed to forge Muslim-Christian brotherhood and show solidarity with Egypt's persecuted Coptic Christian minority.
It comes after a week in which North Korea test-fired a ballistic missile and the US military made several showings of its might, including moving a carrier group into the region.