The Supreme Court on Thursday instructed the government to take steps to return a Salvadoran migrant it had wrongly deported to a notorious prison in El Salvador.

In an unsigned order, the court stopped short of ordering the return of the migrant, Kilmar Armando Abrego Garcia, indicating that courts may not have the power to require the executive branch to do so.

But the court endorsed part of a trial judge’s order that had required the government to “facilitate and effectuate the return” of Mr. Abrego Garcia.

“The order properly requires the government to ‘facilitate’ Abrego Garcia’s release from custody in El Salvador and to ensure that his case is handled as it would have been had he not been improperly sent to El Salvador,” the Supreme Court’s ruling said. “The intended scope of the term ‘effectuate’ in the district court’s order is, however, unclear, and may exceed the district court’s authority.”

The case will now return to the trial court, and it is not clear whether and when Mr. Abrego Garcia will be returned to the United States.

“The district court should clarify its directive, with due regard for the deference owed to the executive branch in the conduct of foreign affairs,” the Supreme Court’s ruling said. “For its part, the government should be prepared to share what it can concerning the steps it has taken and the prospect of further steps.”