WASHINGTON (REUTERS) - The US Supreme Court on Monday (Feb 26) dealt a setback to President Donald Trump, requiring his administration to maintain protections he has sought to end for hundreds of thousands of immigrants brought illegally into the United States as children.

The justices refused to hear the administration's appeal of a federal judge's Jan 9 nationwide injunction that halted Trump's move to rescind a program that benefits immigrants known as "Dreamers" implemented in 2012 by his Democratic predecessor, Barack Obama.

The protections were due to start phasing out beginning in March under the Republican president's action, announced in September.

Under the Deferred Action for Childhood Arrivals (Daca) programme, roughly 700,000 young adult, mostly Hispanics, are protected from deportation and given work permits for two-year periods, after which they must re-apply. Congress so far has failed to pass legislation to address the fate of the "Dreamers," including a potential path to citizenship.

San Francisco-based US District Judge William Alsup ruled last month that Daca must remain in place while litigation over the legality of Trump's action is resolved, prompting the administration's unusual appeal bypassing a federal appeals court and going directly to the Supreme Court.

"The Daca programme - which provides work permits and myriad government benefits to illegal immigrants en masse - is clearly unlawful. The district judge's decision to unilaterally re-impose a programme that Congress had explicitly and repeatedly rejected is a usurpation of legislative authority," White House spokesman Raj Shah said.

"We look forward to having this case expeditiously heard by the appeals court and, if necessary, the Supreme Court, where we fully expect to prevail," Shah added.

The administration argued that Obama exceeded his powers under the Constitution when he bypassed Congress and created Daca.

Alsup ruled that the challengers, including the states of California, Maine, Maryland and Minnesota and Obama's former homeland security secretary Janet Napolitano, were likely to succeed in arguing that the administration's decision to end Daca was arbitrary.

In a brief order, the Supreme Court justices did not explain their reasoning, but said the appeal was "denied without prejudice," indicating they will maintain an open mind on the underlying legal issue still being considered by a lower court, the San Francisco-based 9th US Circuit Court of Appeals. The high court also said it expects the lower court to "proceed expeditiously to decide this case."

Trump, meeting with governors at the White House, took a swipe at the appeals court, which has ruled against him in other key cases, as well as the broader American judiciary.

"Nothing's as bad as the 9th Circuit," Trump said. "It's really sad when every single case filed against us is in the 9th Circuit. We lose, we lose, we lose and then we do fine in the Supreme Court," Trump added.

"But what does that tell you about our court system? It's a very, very sad thing."

'FULLY LEGAL'

California Attorney-General Xavier Becerra, a Democrat, called the administration's bid to bypass the 9th Circuit, which has ruled against Trump on other matters, "unusual and unnecessary."

"We look forward to explaining to the Ninth Circuit court that Daca is fully legal. For the sake of the Dreamers who help make our economy and our state strong, the rescission of Daca should not be allowed to stand," Becerra said in a statement.

The Daca dispute is the latest major case brought to the Supreme Court for its consideration arising from Trump's immigration policies. The justices are due to hear arguments in April on the legality of his latest travel ban order barring entry to people from several Muslim-majority nations.

Greisa Martinez, a Daca recipient who works in Washington with the immigrants' rights group United We Dream, said she was grateful the Supreme Court's action gave people already enrolled in the programme more time, but said most young immigrants who are eligible for the protections have not signed up.

"We need a permanent solution now," Martinez told reporters."This back and forth on Daca and the legislative process has created a crisis in our community."

Justice Department spokesman Devin O'Malley said in a statement that "while we were hopeful for a different outcome," the high court rarely agrees to take up cases before a lower court has ruled, "though in our view it was warranted for the extraordinary injunction requiring the Department of Homeland Security to maintain Daca."

Trump's move to rescind Daca prompted legal challenges by Democratic state attorneys-general and various organisations and individuals in multiple federal courts.

On Feb 13, a second US judge issued a similar injunction ordering the administration to keep Daca in place. US District Judge Nicholas Garaufis in Brooklyn acted in a lawsuit brought by plaintiffs including a group of states led by New York.

Judges Alsup and Garaufis did not say that the administration could not at some point end the programme, only that there was evidence it did not follow the correct procedures in doing so.

The rulings allow those who had previously applied for protections and whose two-year status was soon to expire to apply beyond the deadline set by the administration in September. The original plan put on hold by the court rulings said that only those who re-applied by October and whose status was due to expire by March 5 could re-apply.

The administration is not processing new applications.