WASHINGTON -- The Trump administration admitted Thursday a court ruling prevents it from housing children with their detained parents for longer than 20 days, putting more pressure on Congress to act on immigration.

President Trump once again blamed Democrats, but it was his own party that split on a conservative immigration bill and had to postpone a vote on a second bill that was supposed to be a compromise between the two wings of the GOP.

The compromise bill would allow migrant children to be detained with their parents. It would also provide a pathway to citizenship for some so-called Dreamers, a move some conservatives call amnesty.

As children wrapped in mylar blankets protested on Capitol Hill, Democrats urged the White House to roll back its zero tolerance policy altogether.

"Does anybody really believe that incarcerating children with their parents is the solution?" said Rep. Pramila Jayapal of Washington state.

The president made it clear he is not backing down.

"If we took zero tolerance away, you would be overrun," he said.

But the executive order Mr. Trump signed on Wednesday is not a permanent fix to the separation problem.Court precedent prevents the Justice Department from housing children with their parents for more than three weeks. It can take a year or two for asylum seekers to get a hearing.

"Obviously what we're trying to do is put the families at the head of the queue so that they can be adjudicated faster and have the proper facilities to house them," said House Speaker Paul Ryan.

Ryan has not been willing to entertain a more narrow bill to allow children to be held with their families. He's been pushing the comprehensive bill that includes billions for the president's border wall. But he may have to change approach if he can't round up support before the vote.