The U.N. human rights office is calling on the Trump administration to "immediately halt" its policy of separating children from their parents after crossing U.S. border with Mexico.

Rights office spokeswoman Ravina Shamdasani scolded the U.S. for its "zero tolerance" policy in which some families have been separated after migration across the border.

The rights office said in a statement that "children should never be detained for reasons related to their own or their parents' migration status. Detention is never in the best interests of the child and always constitutes a child rights violation."

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Shamdasani told a U.N. briefing Tuesday that the practice of separating families amounted to an "arbitrary and unlawful" interference in family life, calling it a "serious violation" of the rights of children.