El Salvador’s notification to the UN, however, emphasizes that it does not currently possess jurisdiction over the detainees.

This disclosure adds significant weight to the argument that the Venezuelan detainees — more than 200 men — remain under U.S. authority and protections, despite being physically located in El Salvador.

The development led to strong reactions on social media.

Investigative reporter Jordan Fischer wrote on the social platform X: "Likely to compound DOJ's problems before Judge [Paula] Xinis: Attorneys representing a group of detainees at CECOT just filed in D.C. federal court what they say is a UN report in which El Salvador claimed the 'jurisdiction and legal responsibility' for those detainees lies w/ the U.S."

Aaron Reichlin-Melnick, a senior fellow at the American Immigration Council, wrote: "HUGE! This completely puts to lie the Trump admin’s repeated claims in court that the U.S. has no control over the people we had imprisoned without trial in El Salvador. El Salvador told the United Nations definitively that those people are being held under U.S. jurisdiction."

The X account "@TheWarMonitor" wrote: "El Salvador told the UN it let the US use its prisons under a deal, but says the US is fully responsible for who they locked up or moved. Families want answers."

"Trump, his administration and their mouthpieces, exposed as liars, yet again!" wrote Democratic strategist Maria Cardona.