Manfred Nowak, the Independent Expert for the UN Global Study on Children Deprived of Liberty, reported on Monday that the US has the highest rate of children in detention in the world. He stated that the US has more than 100,000 children in migration related detention.

Nowak also stated that the Trump administration’s separation of children from their parents at the border is in violation of the Convention on the Rights of the Child, which the US has signed but not ratified. Nowak called the practice “inhuman treatment for both the parents and the children.”

Sixty out of every 100,000 children in the US justice or immigration system are detained, which is the world’s highest rate. The average is five per 100,000 in western Europe and 14-15 per 100,000 in Canada.

More than 7 million people under the age of 18 are being held in detention worldwide, 330,000 of which are in immigration related detention. The study asserted that children should only be detained as a last resort and for the shortest possible amount of time.