MORIA, Greece — Pope Francis gave Europe a lesson Saturday in welcoming refugees by bringing 12 Syrian Muslims to Italy aboard his charter plane after an emotional visit to the Greek island of Lesbos, which has faced the brunt of Europe's migration crisis.

Refugees on the overwhelmed island fell to their knees and wept at his presence.

Some 3,000 migrants on Lesbos are facing possible deportation back to Turkey under a new deal with the European Union, and the uncertainty has caused heavy strains.

Francis decided only a week ago to bring three refugee families to Italy after a Vatican official suggested it. He said he accepted the proposal “immediately” since it fit the spirit of his visit to Lesbos.

“It's a drop of water in the sea. But after this drop, the sea will never be the same,” he said of his gesture, quoting one of Mother Teresa's phrases.

During the five-hour trip, Francis implored European nations to respond to the migrant crisis on its shores “in a way that is worthy of our common humanity.”

The Greek island, which is a few miles from the Turkish coast, has seen hundreds of thousands of people land on its beaches and rocks in the last year, fleeing war and poverty at home.

The pope visited Lesbos alongside the spiritual leader of the world's Orthodox Christians and the head of the Church of Greece. They came to give a united Christian message thanking the Greek people for welcoming migrants and highlighting the plight of refugees as the 28-nation EU implements a plan to deport them back to Turkey.

Francis insisted his gesture to bring the 12 refugees to Italy was “purely humanitarian,” not political. But in comments on the flight home, he urged Europe to not only welcome refugees but better integrate them into society, so they are not left in ghettos where they can become prey to radicalization.

Many refugees wept at Francis' feet as he and the two other religious leaders approached them at the Moria refugee detention center on Lesbos, where they greeted 250 people individually. Others chanted “Freedom! Freedom!” as they passed by.

The Vatican said the 12 Syrians, including six children, who went to Rome will be supported by the Holy See and cared for initially by Italy's Catholic Sant'Egidio Community.

They were treated to a raucous welcome Saturday night in Rome, with drummers thumping, a crowd applauding and the mothers of the three families receiving a single red rose.

“I thank you for what you have done,” Nour, a mother of a 2-year-old, said of the pope. “I hope this gesture has an effect on refugee policy.”

Nour and her husband, Hasan, are engineers who lived in Zabadani, a mountainous area near the Lebanese border that has been bombed. Another family with two children is from Damascus, and a third family with three children came from Deir el-Zour, a city close to the Iraqi border that Islamic State has been besieging for months, leading to malnutrition.

Two of the three had their homes bombed, said the Sant'Egidio's refugee chief, Daniela Pompei.

She said the three families had been given Italian humanitarian visas and would now apply for asylum. Francis said they were selected not because they were Muslim but because their papers were in order. They had arrived on Lesbos before the EU deportation date.

At a ceremony in Lesbos to thank the Greek people, Francis said he understood Europe's concern about the migrant influx. But he said migrants are human beings “who have faces, names and individual stories” and deserve to have their most basic human rights respected.

Human rights groups have denounced the EU-Turkey deportation deal as an abdication of Europe's obligation to grant protection to asylum seekers.

The March 18 deal stipulates that anyone arriving clandestinely on Greek islands since March 20 will be returned to Turkey unless they successfully apply for asylum in Greece. For every Syrian sent back, the EU will take another Syrian directly from Turkey for resettlement in Europe.

In return, Turkey was granted billions of euros to deal with the over 2.7 million Syrian refugees living there and promised that its stalled accession talks with the EU would speed up.

During the visit, Francis, Ecumenical Patriarch Bartholomew I and the archbishop of Athens, Ieronymos II, signed a joint declaration urging the world to make the protection of human lives a priority and to extend temporary asylum to those in need. It also called on political leaders to ensure that everyone can remain in their homelands and enjoy the “right to live in peace and security.”

Meanwhile Saturday, Greece's coast guard said a merchant vessel rescued 41 migrants whose boat was found rudderless at sea after sailing from Libya.

The migrants were found about 110 miles off Greece's southwest coast.