Pope Francis has called for a third country, such as Norway, to mediate between North Korea and the US, saying the situation has become "too hot".
Speaking as he departed from a visit to Cairo, the Pope warned that "a good part of humanity" would be destroyed in any war between the two sides.
He said: "I call on - and will call on - all leaders, as I have called on leaders of various places, to work to seek a solution to problems through the path of diplomacy.
"There are so many facilitators in the world, there are mediators who offer themselves, such as Norway for example."
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Norway brokered a deal between Israel and the Palestinians in the early 1990s known as the Oslo Accords.
The Pope also called on the United Nations to re-assert its leadership, saying it had become "too watered down".
He added that he was willing to meet US President Donald Trump when he is in Europe next month but he is not aware of the President having requested this.
North Korea recently test fired a ballistic missile, the third in the past few weeks, and this was described by Mr Trump as being "disrespectful" to China .
Mr Trump also said late last week that there was a chance of "major, major conflict" with North Korea, adding that finding a diplomatic solution was "very difficult".
But Pope Francis warned: "This question of missiles in (North) Korea has been brewing for more than a year but now it seems the situation has become has become too hot.
"We are talking about the future of humanity.
"Today, a widespread war would destroy - I would not say half of humanity - but a good part of humanity, and of culture, everything, everything.
"It would be terrible. I don't think that humanity today would be able to withstand it."