ROME — There is a danger that the Christian presence in the Middle East will disappear, “disfiguring the very face of the region,” Pope Francis said Saturday.

At a major gathering of Orthodox patriarchs and Catholic leaders in the southern Italian port city of Bari, the pope excoriated world leaders for their “murderous indifference” toward the plight of persecuted Christians and others in the Middle East.

This region so full of light “has been covered by dark clouds of war, violence and destruction, instances of occupation and varieties of fundamentalism, forced migration and neglect,” Francis said, and all of this “has taken place amid the complicit silence of many.”

The Middle East has become “a land of people who leave their own lands behind,” the pontiff added, highlighting the danger that “the presence of our brothers and sisters in the faith will disappear, disfiguring the very face of the region.”

“For a Middle East without Christians would not be the Middle East,” he said.

The pope’s words came during his opening address for an ecumenical prayer service, prior to descending with the Orthodox patriarchs into the crypt of the Basilica of St. Nicholas where the relics of the saint—the inspiration for Santa Claus—are kept.

The pope invited his fellow Christian leaders to “live this day with minds and hearts turned towards the Middle East,” where Jesus Christ was born and where “ever-fresh streams of spirituality and monasticism have their source.”

“There ancient and unique rites are preserved, together with an inestimable patrimony of sacred art and theology,” he said. “There the heritage of our great Fathers in the faith lives on. This tradition is a treasure to be preserved to the utmost of our ability, for in the Middle East our very souls are rooted.”

The pope used powerful language to condemn what he sees as the indifference and complicity of many nations in allowing persecution to continue apparently without concern.

“Indifference kills, and we desire to lift up our voices in opposition to this murderous indifference,” Francis said.

“We want to give a voice to those who have none, to those who can only wipe away their tears. For the Middle East today is weeping, suffering and silent as others trample upon those lands in search of power or riches,” he said.

The pontiff’s accusations of indifference would seem to find corroboration in recent surveys.

The distressing results of a poll of American Catholics taken earlier this year found that while 40 percent believe that Christian persecution around the world is “severe,” they are more concerned about poverty, climate change, and the global refugee crisis than the sufferings of their brothers and sisters in faith.

The poll, conducted by Aid to the Church in Need-USA/McLaughlin & Associates, found that four-in-10 Catholics believe that at least half of religion-based attacks around the world are directed at Christians.

Nonetheless, when asked to rank the intensity of their concern regarding global issues, U.S. Catholics placed Christian persecution dead last on the list, with human trafficking garnering 86 percent, poverty 86 percent, climate change 74 percent, refugee crisis 74 percent, and Christian persecution just 69 percent.

“What the survey reveals quite clearly,” said George Marlin, chairman of Aid to the Church in Need-USA (ACNUSA), “is that there is a need to increase the engagement level of the US Catholic Church when it comes to global Christian persecution—both at the grassroots and leadership levels. The issue has to become a priority.”

Follow Thomas D. Williams on Twitter