Pope Francis has said a third country should mediate the dispute between North Korea and the US, which he said had become “too hot”, risking a war in which “a good part of humanity” would be destroyed.

Donald Trump, meanwhile, answered a question in a television interview about whether military action was possible by saying: “I don’t know. I mean, we’ll see.”

The pope, speaking to reporters aboard the plane taking him back to Rome from Cairo, also said he was ready to meet Trump in Europe next month. He added, however, that he was not aware of any request for a meeting.

In answer to a question about North Korean missile tests and military and diplomatic moves by the US, Francis said the United Nations should reassert its leadership because it had become “too watered down”.

“I call on … all leaders … to work to seek a solution to problems through the path of diplomacy,” he said.

North Korea test-fired a ballistic missile on Friday, shortly after the US secretary of state, Rex Tillerson, warned that failure to curb Pyongyang’s nuclear and ballistic missile programmes could lead to “catastrophic consequences”.

The test failed. Trump, who earlier this week said the US could have a “major, major conflict” with North Korea, responded with a tweet. The president wrote: “North Korea disrespected the wishes of China & its highly respected president when it launched, though unsuccessfully, a missile today. Bad!”

In remarks released by CBS ahead of an interview set to be broadcast on Sunday and Monday and part-taped at Trump’s rally in Pennsylvania on Saturday night, the president was asked if diplomatic and military pressure was working.

“Well, I didn’t say, “don’t test a missile’,” Trump said. “[North Korean leader Kim Jong-un is] going to have to do what he has to do. But he understands we’re not going to be very happy.”

Trump said President Xi Jinping of China, “a man that I’ve gotten to like and respect” and whom he met earlier this month in Florida, was also pressuring North Korea.



“But so far,” he continued, “perhaps nothing’s happened and perhaps it has. This was a small missile. This was not a big missile. This was not a nuclear test, which he was expected to do three days ago. We’ll see what happens.”

Trump added: “If he does a nuclear test, I will not be happy. And I can tell you also, I don’t believe that the president of China, who is a very respected man, will be happy either.”

Would that mean military action?

“I don’t know,” said Trump. “I mean, we’ll see.”

On the papal plane, Francis gave a news conference that lasted about 30 minutes. He said: “There are so many facilitators in the world, there are mediators who offer themselves, such as Norway for example. It [Norway] is always ready to help. That is just one but there are many. But the path is the path of negotiations, of a diplomatic solution.

“This question of missiles in [North] Korea has been brewing for more than a year but now it seems the situation 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.”

Trump is due in Sicily on 26 and 27 May for a meeting of the heads of the world’s richest nations. The White House has not yet said if he will stop in Rome to meet the pope, which would be an unusual omission for a visiting head of state.

Asked if he would meet Trump, the pope said: “I receive every head of state who asks for an audience.”