The briefs are due October 5 and the court said for now it is removing from its oral argument calendar a hearing scheduled for October 10.
The Sunday proclamation could be less vulnerable to legal attack, scholars and other experts said, because it is the result of a months-long analysis of foreign vetting procedures by US officials.
The Trump administration says Venezuela's government has been uncooperative in verifying whether its citizens represent national security threats and says the travel restrictions target officials at agencies and ministries responsible for screening.More news: Spain to send extra police to try to halt Catalan referendum
Most citizens of Chad, Libya and Yemen will be blocked from emigrating to or visiting the United States because the countries do not have the technical capability to identify and screen their travelers, and in many cases have terrorist networks in their countries, officials said.
The eight countries with travel restrictions are countries officials said aren't sharing information with the US about terrorism or other issues, or they haven't taken necessary security precautions. For example, while Iran remains on the list of countries with travel restrictions, student and exchange visas are an exception. As part of the presidential proclamation signed on Sunday, the USA will also bar the entry of certain Venezuelan government officials and their immediate families.
Despite the removal of Sudan, this new proclamation is undoubtedly more of the same, meant to appeal to the xenophobia and Islamophobia of Trump's base.More news: USA oil stockpiles grow 4.6 million barrels
Parties in the two cases - Trump v. The restrictions announced are tough and tailored, and they send a message to foreign governments that they must work with us to enhance security. The announcement Sunday came on the same day that Trump's temporary ban on visitors from six Muslim-majority countries was set to expire. A mere tie to a US company or organization, such as a past relationship or a speaking invitation, might not be enough to qualify. The inclusion of Venezuela and North Korea appeared to be an attempt to block challenges from advocacy groups and others who have called the restrictions a ban on Muslims. It is generally assumed the president will at some point release a new policy with respect to refugees, but the timing is uncertain.
The ban on citizens of the six countries was to last 90 days; the ban on refugees was to last 120 days.
"The fact that Trump has added North Korea - with few visitors to the USA - and a few government officials from Venezuela doesn't obfuscate the real fact that the administration's order is still a Muslim ban", said Anthony D. Romero, executive director of the American Civil Liberties Union in a September 24 statement. Subsequently, judges in other federal district courts in Massachusetts, Virginia, and Washington issued similar rulings.More news: Hurricane season isn't over, as Maria is about to follow's Irma's path