The report undercuts months of assertions by senior Trump officials, who have repeatedly claimed they have no power to compel the return of these individuals.

Over 200 migrants who were sent to El Salvador's CECOT mega-prison under accusations that they were members of a violent criminal gang are the responsibility of the United States, the government of El Salvador told a United Nations working group.

The US government said Wednesday it has located a man wrongly deported to El Salvador and whose whereabouts were previously unknown, adding that he is being held in the country’s CECOT maximum-security prison.