The San Francisco-based 9th U.S. Circuit Court of Appeals put on hold a district judge's July 25 ruling that found the regulation violated U.S. law by cutting off asylum for some migrants caught crossing the border illegally.

Biden took office in 2021 pledging to reverse many of the hardline policies of former President Donald Trump, a Republican, but has adopted some Trump-like border measures as his administration has faced record migrant crossings.

Biden's new asylum regulation presumes most migrants are ineligible for asylum if they passed through other nations without seeking protection elsewhere first, or if they failed to use legal pathways for U.S. entry. The measure took effect when Title 42 ended on May 11.

The American Civil Liberties Union (ACLU) and other groups challenged the Biden measure, arguing it unlawfully denied asylum to some migrants caught crossing the border illegally and mirrored Trump-era restrictions that were also blocked in court.

U.S. District Court Judge Jon Tigar - who blocked the previous Trump policies - vacated the Biden regulation, but stayed his ruling for 14 days to allow an appeal.

Tigar said U.S. law does not limit asylum access for people crossing the border illegally and that transit countries to the south do not offer safe and feasible alternatives to migrants.

The 9th Circuit's decision to allow the Biden policy to stay effect does not mean it will ultimately rule in favor of it.

In 2020, the 9th Circuit upheld Tigar's decision to block a similar Trump regulation that restricted asylum for migrants who transited through other countries en route to the United States.

The ACLU could appeal the latest ruling to the U.S. Supreme Court, but conservative justices outnumber liberals 6-3.

(Reporting by Ted Hesson; editing by Mica Rosenberg and Aurora Ellis)

By Ted Hesson