VATICAN CITY - Pope Francis stepped into a growing controversy over President Donald Trump's immigration policies, criticizing the separation of migrant families at the U.S.-Mexican border and saying that "populism" and "creating psychosis" are not the way to resolve migration problems, according to an interview published Wednesday.
Speaking to Reuters news agency, the pope said, "It's not easy, but populism is not the solution."
He strongly backed U.S. Catholic bishops, who have described as "immoral" the Trump administration's policy of discouraging illegal immigration by separating children from their parents at the border.
U.S. authorities have sought to implement Trump's "zero-tolerance" policy on illegal immigration by criminally prosecuting all migrants caught crossing the border without authorization. That has meant jailing adults and sending their children to government shelters. So far, about 2,000 children have been separated from their parents, prompting an outcry at home and abroad.
In the interview Sunday night, the pope also took aim at Italy's new populist government, which has been cracking down on asylum seekers attempting dangerous crossings by boat from Africa.
"I believe that you cannot reject people who arrive," Francis said, according to Reuters. "You have to receive them, help them, look after them, accompany them and then see where to put them, but throughout all of Europe."
He added: "Some governments are working on it, and people have to be settled in the best possible way, but creating psychosis is not the cure. Populism does not resolve things. What resolves things is acceptance, study, prudence."
Last week, the U.S. Conference of Catholic Bishops denounced the Trump administration's "immoral" separation of families and called the crackdown on migrants a "right-to-life" issue. One bishop attending the biannual meeting in Fort Lauderdale, Florida, reportedly suggested "canonical penalties" for Catholics involved in implementing the Trump policies.
In a statement, the conference condemned the "continued use of family separation at the U.S./Mexico border as an implementation of the Administration's zero tolerance policy." It added: "Our government has the discretion in our laws to ensure that young children are not separated from their parents and exposed to irreparable harm and trauma. Families are the foundational element of our society and they must be able to stay together."
In his interview with Reuters, the pope said, "I am on the side of the bishops' conference."
He also warned that aging societies in Europe face "a great demographic winter" without more immigrants. He predicted that Europe "will become empty" if immigration is cut off.
The pope spoke as Trump's policy continued to draw condemnation across U.S. society and around the world.
British Prime Minister Theresa May, answering questions Wednesday before Parliament, told lawmakers: "The pictures of children being held in what appear to be cages are deeply disturbing. This is wrong. This is not something we agree with."
A Labour Party lawmaker, Gavin Shuker, noted that Trump is scheduled to visit Britain next month and asked what it would take for May to rescind the invitation. "President Trump has locked up 2,000 little children in cages and is refusing to release them unless he's allowed to build a wall. He's quit the U.N. Human Rights Council, praised [North Korean leader] Kim Jong Un's treatment of his own people, turned away Muslims. What does this man have to do to have the invitation . . . revoked?
May replied that the visit would go ahead but that "when we disagree with the United States, we tell them so."
Her comments added the voice of America's closest ally to criticism expressed Tuesday by the governments of Mexico, El Salvador and France, as well as the secretary general of the United Nations.
Even Iran's supreme leader, Ayatollah Ali Khamenei, weighed in Wednesday, denouncing the "complete maliciousness" of separating migrant children from parents. "Seeing the images of the crime of separating thousands of children from their mothers in America makes a person exasperated," Khamenei, the top Shiite religious and political authority in Iran, said on his website.
Pope Francis has placed the issues facing migrants and refugees at the center of his papacy, urging countries to be welcoming even as that message faces the head winds of nationalism and border closures in the United States and across Europe. Last year, Francis said it was important that migrants and refugees be offered a "dignified initial accommodation" and that migrants' rights be respected "independent of their legal status."
The pope took his first official trip outside Rome to a small Italian island, with the goal of bringing attention to the deadly journey taken by migrants across the Mediterranean. He has also advocated for the acceptance of migrants while visiting countries such as Poland that have closed their doors. His frequent denunciation of anti-immigration politics has put him at odds with some of Europe's hard-liners, including Italy's powerful interior minister, Matteo Salvini, who has made a point of approvingly referencing not Francis but his more conservative predecessor, Benedict XVI.
Still, the Argentine-born pope, 81, remains very popular with U.S. Catholics, according to research conducted earlier this year by the Pew Research Service, with 84 percent saying they have a favorable opinion of him. Among voters who are Republican or lean to the right, however, 55 percent see Francis as too liberal.
"The pope's voice really strikes a deep chord with many people, all over the world," Michael Czerny, the Vatican's undersecretary for migrants and refugees, said in an interview. "So, when people hear the pope standing up for these people, there is a lot of sympathy. The trouble is, it's a complex reality, and there are people who are fearful, and those fears can be whipped up - and they have been. It's important that he speaks on behalf of people who are otherwise voiceless.
Czerny said that in the case of the separation of children and families, the pope's stance came from "basic humanity and sheer common sense." Czerny added: "I don't think you have to dig deep into religious tradition - though I can't imagine any religious tradition that would condone this. It's not a question of dogma. It a question of humanity."
Branigin reported from Washington. The Washington Post's Karla Adam in London contributed to this report.