WASHINGTON (CNN) — Trump Administration lawyers are asking the U.S. Supreme Court to let a rule, limiting asylum claims, go into effect nationwide.

That, as a lower court blocking it, is appealed. A federal judge had blocked the new Trump Administration rule.

The rule dramatically limits the ability of Central American migrants to claim asylum if they enter the United States by land through Mexico, nationwide.

Earlier in August, the 9th U.S. Circuit Court of Appeals dialed down the nationwide injunction, saying it can only apply to migrants claiming asylum in Arizona and California.

Those states fall under the Nine Circuit’s jurisdiction.

Immigrant advocacy groups oppose the rule, saying it’s unlawful and leaves migrants in harm’s way.