A second federal appeals court in the US has refused to revive President Donald Trump's travel ban. 

The San Francisco-based 9th U.S. Circuit Court of Appeals used narrow grounds to reject the Trump administration's bid to undo a Hawaii federal judge's decision blocking the temporary travel ban.

The court said the president's March 6 order violated existing immigration law, but the three-judge panel did not address whether it was unconstitutional discrimination against Muslims.

On May 25th a Richmond, Virginia-based 4th U.S. Circuit Court of Appeals, upheld a Maryland judge's ruling that also blocked Trump's 90-day ban on travelers from Libya, Iran, Somalia, Sudan, Syria and Yemen.

The Virginia-based court said the language in the executive order itself did not make a rational case for why a travel ban was needed.

The court said: "The order does not offer a sufficient justification to suspend the entry of more than 180 million people on the basis of nationality," referencing the combined populations of the six countries included in the travel ban.