The top U.N. human rights official voiced concern on Monday at the Trump administration’s decision to end the DACA program for immigrants who arrived illegally as children and urged the U.S. Congress to give them lasting legal status in the country.

Referring to a move to end the Deferred Action for Childhood Arrivals (DACA) program in six months, affecting nearly 800,000 young migrants known as “Dreamers”, Zeid Ra’ad al-Hussein told the United Nations Human Rights Council in Geneva:

“I hope Congress will now act to provide former DACA beneficiaries with durable legal status. I am disturbed by the increase in detentions and deportations of well-established and law-abiding immigrants.”

(Reporting by Stephanie Nebehay, editing by Tom Miles)