WASHINGTON — The Trump administration urged the U.S. Supreme Court on Monday to take up the legal battle over the future of DACA quickly, asking the justices to consider the issue even before a federal appeals court has ruled on the program's legality.

If the justices don't act soon, the Justice Department said, it will probably be too late to get the case on this year's docket. In that event, the government would likely be required to keep the program going at least another year.

Short for Deferred Action for Childhood Arrivals, DACA allows children of illegal immigrants to remain here if they were under 16 when their parents brought them to the U.S. and if they arrived by 2007. The Obama-era initiative has allowed 700,000 young people, known as Dreamers, to avoid deportation.

The Trump administration moved to end the program a year ago, but federal courts have blocked that attempt. Following a brief hiatus, the government began accepting renewal applications from DACA participants, which must be filed every two years. But the Trump administration is hoping to overturn the rulings that said DACA must be allowed to continue.

A federal court in San Francisco was the first to say that the government acted illegally in trying to shut it down. The government appealed that ruling to the 9th Circuit Court of Appeals, which heard oral argument May 15. In mid-October, the Justice Department notified the appeals court that if it did not rule on the dispute by the end of October, the government would ask the Supreme Court to take up the case anyway.

The Trump administration tried earlier this year to get the case before the Supreme Court while it was pending in the 9th Circuit. The justices declined that invitation in late February but said they assumed the appeals court would "proceed expeditiously to decide this case."

But in a legal brief filed in the Supreme Court late Monday, Solicitor General Noel Francisco said, "That has not happened."

The court should take the case away from the 9th Circuit and decide it now, Francisco said. "Absent prompt intervention from this court, there is little chance the court would resolve this dispute for at least another year."

Supporters of DACA have been largely successful in their legal fight to keep the program going. Courts in Washington and New York have also blocked the government from shutting it down. The Justice Department asked the Supreme Court to take up those cases now, too, on the fast track.

It normally takes at least two months to get a case to the Supreme Court, ready for the justices to consider whether to hear the appeal. But by mid-January, the court typically has filled up the argument calendar for the term, which ends in late June. So if the California appeals court doesn't rule on the DACA issue soon, there would be little chance of getting the case on the Supreme Court's docket in the current term.

The Supreme Court rarely agrees to hear cases before the appeals courts have ruled. But the government's chances might be better this time, given that the justices said they expected the appeals court to act more quickly than it usually does. The 9th Circuit takes an average of nearly 23 months to issue a final ruling, and only about six months have elapsed since the DACA case was argued. A ruling by the end of the year might be considered expeditious.

Civil rights advocates condemned the Justice Department's action.

"It is clear that Trump will stop at nothing to get what he and extremists have wanted all along — to deport as many people in our communities, including Dreamers, as possible. And to do it as quickly as possible," said Marielena Hincapié, of the NILC Immigrant Justice Fund, an immigrant rights group.