Updated 6:57 p.m. | Bowing to public pressure, President Donald Trump on Thursday signed an executive action ending the practice of separating migrant children from their parents amid a firestorm that saw congressional Republicans break with him.

The president contends Congress must pass legislation addressing the matter for it to be permanently solved given existing laws and court rulings his administration says mandates a process under which migrant children are separated from their parents when caught trying to illegally enter the United States. And it appears families can only be held together for 20 days, unless a federal judge alters a previous ruling placing a limit on detaining migrant families together.

Gene Hamilton, a senior counselor to Attorney General Jeff Sessions, said that judge has a “simple decision” to make in mulling a coming Trump administration request to adjust her ruling to keep the families together longer.

“Are we going to be able to detain alien families together, or are we not?” Hamilton told reporters Wednesday. “It’s clearly lawful, Congress has not passed any statute that prohibits the detention of families together. But the simple fact of the matter is, Judge Gee has put the executive branch into an untenable position.”

Other administration officials reportedly said families already separated will not be reunited.