Declaring "we are all migrants," Pope Francis on Saturday brought a message of hope to thousands of people facing expulsion from Greece as he slammed the world community for failing to end the wars fuelling the crisis.
In an emotional visit that saw people kneeling in tears at the pope's feet, the pontiff told exiles they were "not alone" and pleaded for the world to show "common humanity" following a hardening of the EU's stance on migrants.
And in a clear message to hardline states who have refused to participate in a European Union migrant relocation scheme, the 79-year-old leader of the Catholic Church took with him three Muslim Syrian families whose homes have been bombed.
"You are not alone... do not lose hope," the pope, who was accompanied by Ecumenical Patriarch Bartholomew and Archbishop Ieronymos, the head of the Church of Greece, told migrants at the Moria registration centre, where around 3,000 people are being held.
The vast majority have requested asylum but will likely be deported under a controversial agreement reached last month to tackle Europe's refugee crisis by sending all irregular migrants who land in Greece back to Turkey.
As the pope was escorted through Moria to meet a select number of migrants, one man broke into tears as he knelt at the pontiff's feet, requesting his blessing.
Another woman who slipped past security to approach the pontiff also broke down in tears as he paused to listen to her.
Other migrants gathered outside held handmade signs that read 'We want freedom', 'Let my people go' and 'Papa cherche a nous sauver' ('Pope, try to save us').
A group of small children presented the pope with a dozen drawings.
Lesbos is one of the first ports of call in the EU for the hundreds of thousands of asylum-seekers who have fled war, poverty and persecution in the Middle East and Asia across the Aegean Sea via nearby Turkey in the past year.
The religious leaders held a prayer at Lesbos harbour in memory of the hundreds of migrants who have drowned during the voyage in overcrowded smuggler boats.
"Merciful God...though many of their graves bear no name, to you each one is known, loved and cherished," the pope said.
"May we never forget them, but honour their sacrifice with deeds more than words," he said.
Earlier they signed a declaration calling on the international community to "respond with courage" to the humanitarian crisis and calling on religious communities to step up efforts to assist refugees.
The pope stressed that migrants were not numbers but people with "faces, names and individual stories" who were preyed on by "unscrupulous thugs" and called for "resolute" efforts to clamp down on arms trafficking.