"I am on the side of the bishops' conference," Pope Francis said in an interview with the Reuters news agency, published online June 20. "Let it be clear that in these things, I respect (the position of) the bishops' conference."

On the first day of their June 13-14 spring assembly in Fort Lauderdale, Florida, Cardinal Daniel N. DiNardo of Galveston-Houston, president of the U.S. Conference of Catholic Bishops, read a statement on behalf of the bishops denouncing the government's zero-tolerance policy.

"Families are the foundational element of our society, and they must be able to stay together. While protecting our borders is important, we can and must do better as a government, and as a society, to find other ways to ensure that safety. Separating babies from their mothers is not the answer and is immoral," the statement said.

The political rise of populist movements in both the United States and in Europe has led to a severe crackdown on men, women and children trying to escape war, violence, poverty and persecution.

In Italy, Interior Minister Matteo Salvini banned the NGO rescue ship Aquarius, with more than 600 migrants aboard, to dock and has vowed to stop any foreign boats carrying rescued migrants into the country.

Pope Francis said the current wave of populist rhetoric against migrants was "creating psychosis" and that people seeking a better life should not be rejected.

Europe, he added, is facing a "great demographic winter" and, without immigration, the continent "will become empty."

"Some governments are working on it, and people have to be settled in the best possible way, but creating psychosis is not the cure," he said. "Populism does not resolve things. What resolves things is acceptance, study, prudence."