The pope said he did not know enough about French politics to respond, but, he said, “Europe is in danger of breaking apart, this is true.” He noted that the migrant crisis fueled fears that destabilized the Continent, “but we mustn’t forget that Europe is made by immigrants.”
“Centuries and centuries of immigrants,” he said. “It’s us.”
That inclusive message has proved popular with liberals. But Francis, 80, also repeated language that some have criticized as insensitive or tone deaf.
Asked if he wanted to clarify remarks he made last week at a special prayer event for Christian martyrs when he said that refugee camps were like concentration camps, a comparison criticized by Jewish groups, the pope said, “It wasn’t a slip of the tongue.”
“There are refugee camps that are real concentration camps,” he said, adding, by way of explanation, that the refugees were detained in camps and could not get out.
The pope’s instruction to reporters on the plane that questions be limited to themes touched on during his Egypt visit meant that he skirted some pressing issues facing the Vatican, notably the lack of progress by his commission established to safeguard children from sexual abuse.
But Francis seemed eager to address one pressing geopolitical issue. He urged the United States and North Korea to step away from the brink and avoid a nuclear conflict that could, he said, be disastrous for “the future of humanity.”
His comments came just days after Mr. Trump said in an interview with Reuters that there was a chance “that we could end up having a major, major conflict with North Korea.” The president’s remarks seemed to undercut remarks by others in his administration to ease the dispute by raising the possibility of direct negotiations between the United States and North Korea.
Mr. Trump is scheduled to make his first trip abroad as president in May. His exact itinerary is unclear, but he is expected in Taormina, Sicily, for a meeting of the world’s leading economic powers at the end of the month. A visit with the pope is standard for American presidents traveling to Italy, but the two world leaders have a rocky history.
In February 2016, Francis responded to a question about Mr. Trump by saying, “A person who thinks only about building walls, wherever they may be, and not building bridges, is not a Christian.”
The pope’s view does not seem to have changed. In one of his Cairo speeches, Francis said: “Demagogic forms of populism are on the rise. These certainly do not help to consolidate peace and stability.”
All of that has led to doubts about whether a meeting will actually happen. During a news conference at the White House this month with Prime Minister Paolo Gentiloni of Italy, Mr. Trump said, “I look very much forward to meeting the pope.” Immediately after, Mr. Trump’s spokesman, Sean Spicer, acknowledged that no meeting had been scheduled.
That was still the case as of Saturday evening.
“I still haven’t been informed by the secretary of state that a request has been made,” the pope said, “but I meet every head of state who asks for an audience.”
Francis began the day celebrating an open-air Mass outside Cairo. He told a crowd of 15,000 people who had filled about half of the locked-down Air Defense Stadium that “the only fanaticism believers can have is that of charity.”
“Any other fanaticism does not come from God and is not pleasing to him,” he said.
The pope’s message echoed his strong and extensive remarks during the first day of his two-day trip to Egypt, when, in one of the most influential centers of Sunni Islamic learning, he spoke out against radicalism and the use of religious language as a cloak for terrorism and violence.
On Saturday, he continued in that vein, saying that true faith required “first crucifying our narrow notions of a God who reflects only our own understanding of omnipotence and power.”
“It is better not to believe than to be a false believer, a hypocrite!” he added.
People in white hats emblazoned with the message “Pope of Peace in Egypt of Peace,” waved Egyptian flags and released yellow and white balloons, representing the Vatican colors. Above them, military helicopters circled and Republican Guards in dark camouflage patrolled the perimeter.
“I’m so happy,” said Nabil Shoukry, 55, who wore a scarf adorned with an image of Francis’ face. Mr. Shoukry, a Coptic Orthodox Christian, said he was taking part in the event “for praying.”
That has been a courageous act for Coptic Christians of late, as suicide bombers have attacked their churches, killing scores of worshipers. Francis mourned those victims on Friday night in a haunting ceremony at a cathedral. Saturday’s open-air Mass took place far east of Cairo, amid long arid stretches of rock, garbage piles and desert in the June 30 Stadium. The stadium is named in honor of the 2013 street protests that preceded Mr. Sisi’s ouster of his predecessor, who was supported by the Muslim Brotherhood, and the military takeover of the country.
Antonios Aziz Mina, a Coptic Catholic bishop of Giza, called the pope’s visit a blessing that showed solidarity with Egypt’s Christians, especially those killed in recent months by Islamist extremists. But the bishop showed similar deference to Mr. Sisi, who has cracked down on civil rights and dissent in Egypt, often with the support of the country’s Christian leaders.
“If the Muslim Brotherhood were still around, where would we be?” he said. “We were saved by the skin of our teeth. The Christians and the Muslims, Sisi saved us all.”
On his plane hours later, Francis suggested that his visit to Egypt should not be interpreted as a sign of support for Mr. Sisi. He did not intervene in local politics, the pope said.
“I speak of values,” Francis explained, adding that everyone could judge if the country “brings those values forward.”