Pope Francis traveled to Rome’s city hall Tuesday, encouraging the mayor and her staff to be welcoming toward migrants and anyone who wants to make his home in the capital.

“Rome, over its nearly 2,800 years of history, has been able to welcome and integrate different populations and people from all over the world, belonging to the most varied social and economic categories,” the pope told Mayor Virginia Raggi in his prepared address, “without canceling their legitimate differences, without humiliating or crushing their respective peculiar characteristics and identity.”

“This city has welcomed students and pilgrims, tourists, refugees and migrants from every region of Italy and from many countries of the world,” he said.

In order to live up to its history, Francis said, Rome must be “a beacon of civilization and a teacher of welcome,” holding onto the wisdom “that is manifested in the ability to integrate and to make everyone feel a full participant in a common destiny.”

Pope Francis has made the immigration issue a hallmark of his 6-year papacy, beginning with a 2013 visit to the Italian island of Lampedusa and continuing up to the present day.

In January, the Vatican’s department for migrants and refugees published a collection of the teachings of Pope Francis on immigration, gathered into a massive 488-page tome, titled Lights on the Ways of Hope: Pope Francis Teaching on Migrants, Refugees and Human Trafficking.

Francis has insisted that immigration is central to the gospel message and should never be considered a second-tier moral issue.

“We often hear it said that, with respect to relativism and the flaws of our present world, the situation of migrants, for example, is a lesser issue,” Francis wrote in a 2018 teaching letter bearing the title Gaudete et Exsultate (“Rejoice and Be Glad”).

“Some Catholics consider it a secondary issue compared to the ‘grave’ bioethical questions,” he said, which is unacceptable for Christians.

“That a politician looking for votes might say such a thing is understandable, but not a Christian, for whom the only proper attitude is to stand in the shoes of those brothers and sisters of ours who risk their lives to offer a future to their children,” he said.

“Can we not realize that this is exactly what Jesus demands of us, when he tells us that in welcoming the stranger we welcome him?” he asked.

In his City Hall address Monday, Francis said that in the present day Rome’s urban peripheries and other suburbs “have seen the arrival of numerous migrants from many countries, who have fled wars and misery and seek to rebuild their existence in conditions of security and a dignified life,” he said.

“Rome, a hospitable city, is called to face this epochal challenge in the wake of its noble history; to use its energies to welcome and integrate, to transform tensions and problems into opportunities for meeting and growth,” he said.

Rome knows how to draw from its culture “the resources of creativity and charity necessary to overcome the fears that risk blocking possible initiatives and paths,” he said. “These could make the city flourish, unite and create opportunities for development, both civic and cultural, as well as economic and social.”

“Rome, city of bridges, never walls!” he said, a curious statement from the leader of the world’s only walled-in country.