WASHINGTON (NYTIMES) - The Supreme Court on Monday (Dec 4) allowed the third version of the Trump administration's travel ban to go into effect while legal challenges against it continue.

The decision was a victory for the administration after its mixed success before the court over the summer, when justices considered and eventually dismissed disputes over the second version.

The court's brief, unsigned orders on Monday urged appeals courts to move swiftly to determine whether the latest ban was lawful.

Justices Ruth Bader Ginsburg and Sonia Sotomayor said they would have denied the administration's request to allow the latest ban to go into effect.

The court's orders mean that the administration can fully enforce its new restrictions on travel from eight nations, six of them predominantly Muslim.

For now, most citizens of Iran, Libya, Syria, Yemen, Somalia, Chad and North Korea will be barred from entering the United States, along with some groups of people from Venezuela.

The restrictions vary in their details, but in most cases, citizens of the countries will be unable to emigrate to the United States permanently and many will be barred from working, studying or vacationing here.

Iran, for example, will still be able to send its citizens on student exchanges, though such visitors will be subject to enhanced screening. Somalis will no longer be allowed to emigrate to the United States, but may visit with extra screening.

The Supreme Court's orders effectively overturned a compromise in place since June, when the court said travellers with connections to the United States could continue to travel here notwithstanding restrictions in an earlier version of the ban.

The orders gave no reasons for the court's shift. The move did suggest that the administration's chances of prevailing at the Supreme Court when the justices consider the lawfulness of the latest ban have markedly increased.

In a pair of filings in the Supreme Court, Solicitor General Noel J. Francisco said Mr Trump had acted under his broad constitutional and statutory authority to control immigration when he issued a new proclamation in September announcing the new travel restrictions.

Mr Francisco wrote that the process leading to the proclamation was more deliberate than those that had led to earlier bans, issued in January and March. Those orders were temporary measures, he wrote, while the proclamation was the product of extensive study and deliberation.

Lawyers with the American Civil Liberties Union, which represents people and groups challenging the ban, told the justices that little had changed.

"The proclamation is the third order the president has signed this year banning more than 100 million individuals from Muslim-majority nations from coming to the United States," they wrote.

In October, federal judges in Maryland and Hawaii blocked major parts of the latest ban while legal challenges proceed.

"A nationality-based travel ban against eight nations consisting of over 150 million people is unprecedented," wrote Judge Theodore D. Chuang of the US District Court in Maryland.

Citing statements from Mr Trump, some made as a presidential candidate and some more recent, Judge Chuang found that the new proclamation was tainted by religious animus and most likely violated the Constitution's prohibition of government establishment of religion.

Similarly, Judge Derrick K. Watson of the US District Court in Honolulu found that the September proclamation "suffers from precisely the same maladies as its predecessor", adding that it "plainly discriminates based on nationality" in violation of federal law "and the founding principles of this nation".

The administration has appealed both decisions to federal appeals courts in Seattle and Richmond, Virginia. Arguments in those appeals are scheduled for this week.

Judge Chuang limited his injunction to exclude people without "a credible claim of a bona fide relationship with a person or entity in the United States", quoting from a Supreme Court order issued in June concerning the second travel ban.

Judge Watson did not impose such a limitation, but an appeals court modified his injunction, also quoting the Supreme Court's language.

Lawyers for Hawaii, which is challenging the ban, told the justices that there was no reason to make changes now.

"Less than six months ago, this court considered and rejected a stay request indistinguishable from the one the government now presses," they wrote. "But the justification for that dramatic relief has only weakened. In place of a temporary ban on entry, the president has imposed an indefinite one, deepening and prolonging the harms a stay would inflict."

Mr Francisco asked the justices to allow every part of the third ban to go into effect. The second version of the travel ban, he wrote, "involved temporary procedures before the review was conducted and in the absence of a presidential determination concerning the adequacy of foreign governments' information-sharing and identity-management practices."

"Now that the review has been completed and identified ongoing deficiencies in the information needed to assess nationals of particular countries," he wrote, "additional restrictions are needed."