VATICAN CITY (RNS) Pope Francis has called on European leaders not to turn their back on refugees and migrants despite the cultural and security challenges associated with the arrival of one million people over the past year.

Francis has made concern for migrants a centerpiece of his papacy, and on Monday (Jan. 11) in his annual address to diplomats accredited to the Holy See he again urged governments to “overcome the inevitable fears associated with this massive and formidable phenomenon.”

“The massive number of arrivals on the shores of Europe appear to be overburdening the system of reception painstakingly built on the ashes of the Second World War, a system that is still an acknowledged beacon of humanity,” he said in the wide-ranging, 45-minute address.

It is a crisis that recalls the epic stories of mass migrations in the Bible, Francis said, with people fleeing powerful forces to seek safety and freedom, often at a terrible cost.

"Now as then, we hear Rachel weeping for her children who are no more," he said, a reference to passages from both Jeremiah and the Gospel of Matthew.

"Hers is the plea of thousands of people who weep as they flee horrific wars, persecutions and human rights violations, or political or social instability, which often make it impossible for them to live in their native lands," Francis told the diplomats.

"It is the outcry of those forced to flee in order to escape unspeakable acts of cruelty towards vulnerable persons, such as children and the disabled, or martyrdom solely on account of their religion."

More than one million people arrived in Europe by sea last year, the vast majority from the world’s top 10 refugee-producing countries. An estimated 3,771 people died or went missing attempting the crossing.

In his speech, which one Vatican observer characterized as the "geopolitics of mercy and realism," Francis highlighted the “immense influx and the inevitable problems it creates,” such as countries’ capacity to accommodate newcomers and the challenges to cultural and social norms.

“Equally significant are fears about security, further exacerbated by the growing threat of international terrorism,” he said, nodding at the powerful anti-immigrant sentiments that have inflamed debates in Europe and North America.

Such questions have been especially prominent in Germany this month following attacks on women in German cities on New Year’s Eve believed to have been carried out principally by asylum seekers or illegal migrants.

On Sunday, a group of Pakistanis and a Syrian were attacked in separate incidents in Cologne apparently in retaliation.

While not addressing these incidents specifically, Francis said governments have a “two-fold moral responsibility” to protect both citizens and migrants.

“The phenomenon of migration raises a serious cultural issue which necessarily demands a response,” said the pontiff, arguing that new arrivals needed to respect the values, traditions and laws of their host country.

In turn, he said, those societies hosting migrants must acknowledge the “beneficial contribution” a migrant can bring to a community.

Francis praised a number of countries for their acceptable of refugees, particularly Lebanon and Jordan which between them have given haven to 1.7 million Syrians. He also highlighted the efforts made by Turkey, Greece and Italy, telling diplomats that nations in the forefront of the current crisis should not be left alone.

The pope directed strong criticism to states for failing to address the multiple causes of migration, which he said led to disasters which could have been prevented.

“Before it is too late, much could be done to end these tragedies and to build peace,” he said. “But that would mean rethinking entrenched habits and practices, beginning with issues involving the arms trade, the provision of raw materials and energy, investment, policies of financing and sustainable development, and even the grave scourge of corruption.”

The lack of legal avenues for people to reach Europe has led many to turn to smugglers, which make huge profits from the risky sea journey.

Describing the dangerous and traumatic experiences suffered by migrants, Francis said governments must act to put a stop to the trade: “I once more appeal for an end to trafficking in persons, which turns human beings, especially the weakest and most defenseless, into commodities.

“The image of all those children who died at sea, victims of human callousness and harsh weather, will remain forever imprinted on our minds and hearts.”

He also deplored the "idols of profit and consumption" that sacrifice people — from the unborn to the elderly to migrants — to a "culture of waste" that heedlessly discards even food while so many go hungry.