The migration of unaccompanied children into the U.S. is a "humanitarian crisis" that demands a "comprehensive response" from the government, said the head of the U.S. bishops' immigration committee.

"These children are extremely vulnerable to human traffickers and unscrupulous smugglers and must be protected," said Auxiliary Bishop Eusebio Elizondo of Seattle, who chairs the U.S. bishops' Committee on Migration.

"Young lives are at stake," he emphasized.

About 60,000 children from Mexico and Latin America are expected to cross the U.S.-Mexico border in 2014, CBS News reports. U.S. government statistics indicate that over 47,000 unaccompanied minors were apprehended at the border in the 2014 fiscal year, a 90 percent increase over the previous fiscal year.

Bishop Elizondo said in a June 4 statement that child migration is "a very complicated problem" whose roots must be addressed both by the U.S. government and by governments in the region.

He said increasing violence from gangs and organized crime in the young migrants' home countries must be examined.

"This is an issue which should not become politicized or give cause for negative rhetoric," the bishop said.

Momentum behind immigration reform increased last year as a bipartisan "Gang of Eight" senators worked together to introduce legislation aimed at both providing a path to citizenship for undocumented immigrants and securing the U.S. border. In June 2013, the Senate approved the bill in a bipartisan 68-32 vote. However, it stalled in the House of Representatives amid sharp divisions within Republican lawmakers.

The U.S. bishops' conference has laid out several goals for comprehensive immigration reform, including an "earned legalization program" with an "eventual path to citizenship" for those who pass background checks and pay a fine, along with "targeted, proportional, and humane" enforcement measures.

The conference has also called for a program to help low-skilled migrant workers to enter and work in the U.S. legally, as well as the restoration of due process protections for immigrants, an emphasis on family unification, and policy changes to address the deeper causes of immigration.

Archbishop Joseph E. Kurtz of Louisville, president of the U.S. bishops' conference, reiterated the call for immigration reform days before the bishops' spring assembly begins in New Orleans.

"As pastors, we see the human consequences of this broken system each day in our parishes and social service programs, as families are separated, migrant workers are exploited, and our fellow human beings risk everything to find a better life for themselves and the ones they love," he said June 5.

"Our nation should no longer tolerate an unjust system."

Archbishop Kurtz quoted Pope Francis' words that migrants "do not only represent a problem to be solved, but are brothers and sisters to be welcomed, respected and loved."

He pledged support for Congress in reforming immigration law "in a manner that properly balances the protection of human rights with the rule of law."