The United Nations human rights chief on Friday expressed shock at recent “systematic abuses” of migrants by US authorities and urged Washington to “end the practice of separating families.”

UN human rights chief Volker Turk has said that the “dehumanizing and mistreatment of migrants and refugees is unacceptable to the United States.” He called for ensuring that US immigration policies and enforcement practices respect human dignity and the right to due process. “I am appalled by the current routine mistreatment and humiliation of migrants and refugees in the US,” he said in a statement.

“Where is their self-respect and concern for our common humanity?” he asked.

President Donald Trump’s Republican administration is pressing ahead with its campaign to deport millions of illegal immigrants across the country. Thousands of Immigration and Customs Enforcement (ICE) agents have been deployed to Democratic-led Minneapolis.

He expressed outrage over the detention of a five-year-old boy on Thursday in a massive immigration crackdown by Democrats and local authorities in Minneapolis. Minneapolis has been gripped by increasingly tense protests since federal law enforcement officers shot and killed U.S. citizen Renee Good on January 7, while Trump and his officials have defended the shooting as legitimate self-defense.