Donald Trump
Donald TrumpReuters

A federal appeals court in San Francisco denied an emergency motion filed by the US Justice Department to reinstate US President Donald Trump's frozen travel ban.

The temporary ban barred nationals of seven ISIS-ridden countries from entering the US.

"Appellants' request for an immediate administrative stay pending full consideration of the emergency motion for a stay pending appeal is denied," wrote the US Court of Appeals for the Ninth Circuit.

The court asked those against the ban to respond to Trump's appeal, and for the Justice Department to file a counter-response by Monday afternoon.

Acting Solicitor General Noel Francisco on Saturday night said only the US President has the power to decide who can enter or stay in the United States.

Trump tweeted, "Because the ban was lifted by a judge, many very bad and dangerous people may be pouring into our country. A terrible decision.

"Why aren't the lawyers looking at and using the Federal Court decision in Boston, which is at conflict with ridiculous lift ban decision?

"The judge opens up our country to potential terrorists and others that do not have our best interests at heart. Bad people are very happy!"

The US Justice Department said, "Judicial second-guessing of the President’s national security determination in itself imposes substantial harm on the federal government and the nation at large" and warned the decision may harm Americans by "thwarting the legal effect of the public’s chosen representative."

On Friday, Seattle Federal Judge James Robart issued a restraining order on Trump's ban, allowing previously barred individuals to freely enter the US. On Saturday, the Justice Department filed an appeal to overturn Robert's ruling and reinstate the ban.