A U.S. judge expressed frustration on Friday that President Donald Trump's administration had yet to provide sufficient details about its efforts to bring back a man deported in error from the United States and sent to a prison in El Salvador.

Judge Paula Xinis pressed Trump officials in court on Friday about state secret privilege and apparent stonewalling of the case.

U.S. District Judge Paula Xinis said the government’s refusal to provide certain information in the case has been “an exercise in utter frustration.”