Recently I visited a youth detention center in South Carolina. As I entered the facility, I saw a line of boys in jumpsuits march past with their arms behind their backs. The guard explained to me that they make the boys march to "help teach them discipline and structure."

Although I have visited numerous youth jails and prisons over the last 20 years, I am still amazed at how people who work in youth detention centers delude themselves. Young people, many who have experienced unspeakable trauma, come into these facilities in handcuffs and leg irons, are strip searched, and are put in cinder block cells – where sometimes they are physically restrained or locked in isolation for days as punishment – and somehow they are going to come out OK because they are trained to march in prison.

So it's not surprising that in a report released and presented this week to the U.N. Human Rights Council, Juan Mendez, the U.N.'s special rapporteur on torture, sharply criticized the U.S. model of youth detention where children are at "heightened risk of violence, abuse, and acts of torture or cruel, inhuman or degrading treatment or punishment." Even short periods of detention undermine a child's psychological and physical wellbeing. The report points out that children's healthy development requires developing emotional connections to caring adults, a requirement that most institutions consistently fail to meet.

The United State is the biggest jailer of children in the world. More than 67,000 unaccompanied children are locked up in our country's immigrant detention centers. An additional 60,000 children who come in conflict with the law are incarcerated in our juvenile jails or prisons – nearly two-thirds are held for non-violent offenses, including theft, drug possession, or skipping school. And thousands of more children are locked up in adult jails and prisons in the United States. Children of color are over-represented in detention, particularly among youth serving extreme sentences.

Notably, Mendez, who himself is a torture survivor , singles out the United States for being the only nation in the world that sentences children to die in prison. Although the Supreme Court recently banned mandatory life sentences for juveniles, there are approximately 2,500 individuals across the United States who are currently serving life-without-parole for crimes committed as children. In addition to life sentences, "sentences of extreme length have a disproportionate impact on children and cause physical and psychological harm that amounts to cruel, inhuman or degrading punishment."

About 40 percent of children are incarcerated in private facilities that are often euphemistically referred to as treatments centers, camps, or learning academies. The U.N. special rapporteur points out that these private institutions often avoid state oversight and regulation, which may lead to rampant abuse.

The report makes several key recommendations including eliminating juvenile life-without-parole sentences for children and the detention of immigrant children. There should be no use of restraints or solitary confinement under any circumstances. No children should be tried in adult court, and all children should be held in age-appropriate facilities.

In addition, because detention hampers the healthy development of children, the report recommends restricting detention to the shortest period of time possible and limiting it only to exceptional cases. In most cases, states should adopt non-custodial alternatives to detention. These community-based alternatives are not only better for children but cheaper and better for society as a whole.

Unfortunately, the U.S. delegation to the Human Rights Council failed to respond to Mr. Mendez report and preferred to highlight human rights concerns abroad . U.S. leadership on the international stage suffers when we decline to constructively engage and fully cooperate with international human rights bodies. As the U.S. seeks another term as member of the Human Rights Council, it should heed Mendez recommendations and live up to its commitments to uphold human rights at home and abroad .