Migration has become a flash point around the world in recent years, as millions of people have been displaced by wars in Syria and Afghanistan and economic deprivation in Africa, many seeking a better future in Europe.

Immigration has spurred a bitter backlash as nations seek to put up fences and walls, and it has prompted debate in the United States over how to handle asylum seekers from Central America. In Asia, the oppression and dispersion of the Rohingya minority in Myanmar has become a humanitarian crisis.

Even as the pope spoke, Italian news outlets reported that at least seven migrants had drowned in a shipwreck off Morocco over the weekend and others were missing off the Libyan coast, the latest of thousands who have died trying to reach Europe. According to the International Organization for Migration, there have been more than 2,300 migrant fatalities worldwide this year alone.

Francis has emerged as a champion of refugees and migrants. Soon after his election in 2013, he denounced the “globalization of indifference” in a landmark visit to the Mediterranean migrant hub of Lampedusa. Since the European migrant crisis of 2015, the pontiff has consistently promoted the need to welcome refugees, who he believes have been exploited by nationalists.

In his address on Sunday, the pope said that individualism and a utilitarian mentality had produced a “globalization of indifference” in which “migrants, refugees, displaced persons and victims of trafficking have become emblems of exclusion” and are “considered the source of all society’s ills.”

He warned that fear of the unknown, of “migrants and refugees knocking on our door in search of protection, security and a better future,” could lead to intolerance, closed-mindedness and racism.

He said the presence of migrants and refugees, and of those considered vulnerable, offered an opportunity “to recover some of those essential dimensions of our Christian existence and our humanity that risk being overlooked in a prosperous society.” In showing concern for migrants, he said, “we also show concern” for all others.