Pope Francis urged Catholic bishops in the United States to open their doors to immigrants, asserting that “these people will enrich America and its Church.”

As a Latin American, the Pope apologized for “pleading my own case,” when speaking about the influx of Hispanic immigrants into the United States. He also thanked the bishops for the work they have done for immigrants in this country.

The Pope delivered a long address to the bishops gathered for a midday prayer service at Saint Matthew’s Cathedral in the nation’s capital on Wednesday. The address, delivered in Italian, was woven through with religious language, and encouraged the bishops, particularly in their spiritual mission.

“From the beginning,” Francis said, “you have learned their languages, promoted their cause, made their contributions your own, defended their rights, helped them to prosper, and kept alive the flame of their faith.”

“Perhaps you will be challenged by their diversity,” he said. “But know that they also possess resources meant to be shared. So do not be afraid to welcome them.”

The Pope also urged the bishops to offer immigrants “the warmth of the love of Christ.”

He also praised them, saying that “no American institution does more for immigrants than your Christian communities.” The Church in the United States “knows like few others the hopes present in the hearts of these ‘pilgrims,’” Francis said, adding “as a pastor from the South, I feel the need to thank and encourage you.”

In his speech at the White House earlier Wednesday, Pope Francis identified himself as “the son of an immigrant family,” happy to be a guest in this country, “which was largely built by such families,” but went no further into the embattled question of immigration.

By reserving his stronger words on immigration for the U.S. Bishops, the Pope stressed the religious and pastoral aspects of work with immigrants, rather than wade into the more contested legal and political dimensions to the problem.

The Catechism of the Catholic Church teaches that “more prosperous nations are obliged, to the extent they are able, to welcome the foreigner in search of the security and the means of livelihood, which he cannot find in his country of origin.”

At the same time, the Church does not endorse an open-borders approach to immigration, but affirms states’ sovereign rights to protect and secure their borders. The Catechism continues:

Political authorities, for the sake of the common good for which they are responsible, may make the exercise of the right to immigrate subject to various juridical conditions, especially with regard to the immigrants’ duties toward their country of adoption. Immigrants are obliged to respect with gratitude the material and spiritual heritage of the country that receives them, to obey its laws and to assist in carrying civic burdens.

The Church’s insistence on the obligation of immigrants to respect the laws of the countries into which they wish to migrate, provides an important counterweight to a platform that merely emphasizes the rights of immigrants.

Illegal immigration has never been a part of Catholic teaching, and is not supported by Pope Francis, despite his encouragement of nations to be welcoming to those seeking political asylum or simply a better life.

In dealing with Europe’s immigration crisis, Francis has encouraged Catholic institutions on the continent to each host a family of refugees. The Vatican itself has taken in one Syrian family and intends to receive another.

Obviously,” Francis said, “if a refugee comes with all the appropriate security measures in place we must receive him, because it is a commandment in the Bible. Moses tells his people: ‘Receive the stranger because remember that you were once strangers in Egypt,’ right?”

Security against Islamic terrorism is a growing problem, Francis said, without mentioning Islam by name.

“I have to acknowledge that territorial security conditions are not the same today as they were in other times,” he said. “Just 400 km to the south of Sicily we have an extraordinarily brutal terrorist group [in Libya], and then we have the danger of infiltration, right?”

Follow Thomas D. Williams on Twitter @tdwilliamsrome