LESBOS, Greece — Pope Francis returned Sunday to a refugee camp on the Greek island of Lesbos, the site of one of the definitive moments of his papacy, seeking to elevate the plight of migrants — what he called a “shipwreck of civilization” — to the top level of global concerns, along with the pandemic and climate change.

“Five years have passed since I visited this place,” Francis said in a tent overlooking the camp, where he walked through white United Nations containers serving as asylum seekers’ homes. In 2016, he took 12 refugees home with him to Rome. This time, he offered comfort and solidarity to families who had been stuck there for years. “After all this time,” he added, “we see that little has changed with regard to the issue of migration.”

Francis’ remarks came at one of the concluding, and in many ways culminating, events of a five-day trip to Cyprus and Greece meant to renew focus on migration, an issue he has never wavered on, even as the world’s attention has faltered. And when the world has paid attention, it has usually been in a way opposite from how he had hoped.

Migrant flows have fueled nationalist and populist surges in majority-Catholic countries like Italy and Poland. Hungary has claimed that its antimigrant policies and border towers protect Christian culture. And while Europe’s populist season has somewhat abated, a politically amenable hard line against asylum seekers has seeped into the status quo.

Cracking down on migrants has emerged as an election issue in recent weeks in France, a country with a percentage of migrants lower than many of its neighbors, even as desperate people have died trying to cross the English Channel. Britain, their destination, has taken steps to keep them out.

Belarus used migrants as pawns to destabilize the European Union on its eastern border, where Poland, far from welcoming them in, fought them off with water cannons in the freezing cold. Barbed-wire fences demarcate borders, and the bloc, in an effort to keep politically destabilizing waves of migrants at bay, has outsourced its surveillance and detention of migrants to often brutal camps off the continent.

Beyond that, concerns about the coronavirus and the new Omicron variant have led to limits on travel and to more trepidation about strangers at the door.

Through all of this, Francis has remained consistent, even as his calls to welcome strangers have become ever more discordant.

On Sunday, he argued that the intractable reality of the issue exposed both the failure of stopgap measures and the need for a coordinated global response. He denounced an “indifference that kills” in Europe, which he said has shown a “cynical disregard that nonchalantly condemns to death those on the fringes.”

He called European proposals to pool funds for measures to keep migrants at bay “distressing” and, addressing young children in the tent and invoking the images of dead children washed up on shores in recent years, said that because of Europe’s turning away, “the Mediterranean Sea, cradle of so many civilizations, now looks like a mirror of death.”

All around him at the Mavrovouni camp, Greek police and military officers stood sentry over white gravel corridors lined with prefabricated buildings stenciled with addresses in black spray paint.

Outside the doors, asylum seekers left sandals and strollers, stacks of water bottles and bicycles. They held their children and ignored stray dogs, looking up toward the white tent where the pope spoke, slightly above the camp on the edge of the sea.

Before Francis arrived, Camille Mobaki, 31, who said he had escaped persecution in the Republic of Congo, waited in line to get into the tent. “I’m waiting to see if the pope can take some of us to Italy,” said Mr. Mobaki, who has been on Lesbos for two years and who said that his applications for asylum had twice been rejected.

Inside the tent, Voldi Lang Lubaki, 11, sat with her parents and sister. She said she had no idea whether the pope’s being there meant they would be able to leave.

“Maybe it’s yes, maybe it’s no — I hope so,” she said. Asked where she wanted to go, she replied, “Wherever the pope tells me.”

Neither the pope nor the Vatican announced any new transfers from Lesbos, though days earlier, while Francis was in Cyprus, the Vatican said 12 migrants kept there would be relocated to Italy in the coming weeks. Cypriot officials have said 50 would eventually leave the island as part of the agreement.

In the years after the pope’s initial visit to Moria — the horrid camp on Lesbos that stained the name of the island, previously famous for its ancient lyric poets — it swelled to 20,000 people. Moria became notorious for abuses, violence, sexual assault, overall degraded living conditions and then restrictions brought on by the pandemic.

Some of the migrants set fire to the camp in September last year, destroying it and leaving homeless the 12,000 people, mostly Afghans, who had been living there.

Now, only about 2,000 migrants live on Lesbos in what Greek government officials have heralded as a vast improvement and indicative of Greece’s meeting the needs of migrants.

The Greek president, Katerina Sakellaropoulou, who spoke before Francis on Sunday, called his visit a “strong message of hope and responsibility that is conveyed from Lesbos to the international community.”

But the camp is a temporary one until a de facto detention center, paid for by the European Union, is built. Such centers are operating on three other Greek islands, on Leros, Kos and Samos, across a narrow strait from Turkey.

Last year, as the Samos detention center was being built in the center of the island, Jalila Sarhan, 57, from Syria, sat on a hill overlooking overcrowded encampments that came to be known as The Jungle, which competed with Moria for Europe’s bleakest migrant camp.

“It’s too cold, and we get sick,” she said, as all around her men chopped firewood or molded earthen stoves. Women, many of them pregnant, kept their eyes on the thousands of children wandering up and down the hillside.

That encampment was evacuated this year. But moving people around to different detention centers and islands, the Greek government has acknowledged, is not a solution.

“It’s a problem that is here to stay, not only for Greece, but for Europe,” Giorgos Koumoutsakos, a Greek lawmaker, said in an interview in Athens last year, when he was deputy migration minister. He blamed his predecessors in the leftist Syriza government, who he said ignored the security dimension of what they treated as a solely humanitarian issue.

The current government instead has cracked down, erecting a wall along part of the country’s land border with Turkey and intercepting boats transporting migrants from Turkish waters.

Human rights groups have accused Greek border agents of brutalizing migrants and forcibly pushing them back into Turkey. Last week, a legal European Union resident working as an interpreter for the bloc’s border agency, Frontex, accused Greek border guards of mistaking him for an asylum seeker, assaulting him and then forcing him into Turkey alongside dozens of migrants.

On Lesbos, the government spent days cleaning up the camp before Francis’ arrival.

“Why is the pope going to this part of the camp?” asked Ramat Ababsi, 25, who watched the activity around the tent on the hill with bemusement. An Afghan asylum seeker who said that he had been on Lesbos for three years, Mr. Ababsi said several of the prefabricated containers that the police guarded were unused, and indeed several were empty, filled only with bunk bed frames. “The bad situation is on the other side,” he said, gesturing to a section behind him. “The pope should be going over there.”

But wherever Francis has gone, he has implored a reluctant world to open its eyes to the reality facing asylum seekers.

“It is an illusion to think it is enough to keep ourselves safe, to defend ourselves from those in greater need who knock at our door,” Francis said, adding, “Let me repeat: History teaches this lesson, yet we have not learned it.”