The US Justice Department late on Saturday asked a federal appeals court to set aside a judge's order that temporarily blocked the Trump administration's travel ban. The federal government's request for an emergency stay was filed with the 9th US Circuit Court of Appeals.

To justify its appeal, the Justice Department argued that the ruling halting the ban posed an immediate harm to the public, called the president's national security judgment into question, and thwarted enforcement of an executive order.

The ruling on Friday by District Judge James Robart temporarily halted an executive order signed by President Donald Trump that suspended America's refugee program and immigration to the US from seven Muslim-majority countries.

Robart's ruling was a first step in considering the merits of the case challenging the ban.

US officials have said up to 60,000 foreigners have so far had their visas "provisionally revoked" to comply with Trump's order.

'Ridiculous' opinion

Trump on Saturday showed no signs of backing down, tweeting: "What is our country coming to when a judge can halt a Homeland Security travel ban and anyone, even with bad intentions, can come into US?"

"The opinion of this so-called judge, which essentially takes law-enforcement away from our country, is ridiculous and will be overturned!" Trump said on Twitter early on Saturday.

Trump has said "extreme vetting" of refugees and immigrants is needed to prevent terrorist attacks.

A window of opportunity

Rights groups said visa-holders from the seven countries affected by Trump's travel ban should travel immediately because of uncertainty over whether the Justice Department would be granted an emergency freeze of the order issued by Robart.

"We're telling them to get on the quickest flight ASAP," Rula Aoun, director of the Arab American Civil Rights League in Dearborn, Michigan, said.

Her group filed a lawsuit on Tuesday in the federal court in Detroit asking a judge to declare Trump's immigration order unconstitutional.

Some airlines reportedly were not letting some people from the seven countries board their planes.

Protesters took to the streets in several cities to protest the ban on Saturday. Thousands gathered at Denver's City Center Park, carrying signs, chanting and singing. Meanwhile, legal advocates waited at airports to offer assistance to new arrivals in case anything went wrong.

jbh,tj/bw (AP, Reuters)