In addition, policies that involve criminalizing and detaining child migrants "are an insult to human dignity" and are "the dramatic evidence of existing inequalities and failing systems," said Archbishop Ivan Jurkovic, Vatican observer to U.N. agencies in Geneva.

"The grave error of the detention model is that it considers the children as sole, isolated subjects responsible for the situations in which they find themselves and over which they have little, if any, control," the archbishop said. "This model wrongly absolves the international community at large from responsibilities that it regularly fails to fulfill."

Archbishop Jurkovic spoke about the plight of child migrants during a U.N. Human Rights Council panel discussion June 9 on "Unaccompanied migrant children and adolescents and human rights."

Children forced to flee without the protection of their parents or family members, he said, are given no options for a better life and are often "left at the lower levels of human degradation" due to lack of education and health care.

"They must be considered children first and foremost, and their best interest must be a primary consideration in all actions concerning them," Archbishop Jurkovic said.

The practice of detaining and criminalizing migrant children should "never be an option" given that such a practice, even if for a brief period, "can have lifelong consequences on a child's development," he said.

While the protection of all migrating people is "vital and essential, it is not enough," Archbishop Jurkovic added. The international community must step up its efforts to address the situations that force children to flee their homelands, situations that include war, violence, corruption, poverty and environmental disasters.

"A farsighted approach is urgently needed to tackle the tragic and intolerable situations that drive such a drastic increase in the number of children who abandon their lands of birth and search alone for refuge and hope for the future," he said.

Archbishop Jurkovic urged world leaders to promote an integral human development for the "hundreds of millions of children who are living in appalling conditions."

"Even while we are engaged in discussion and debate today, any number of these children will have joined the already huge odyssey of children on the move – simply in search of safety, peace and of a fair chance in life," he said.