The Biden administration said it could no longer wind down the so-called Title 42 policy by Wednesday, even if the Supreme Court allowed it to follow through on a lower court’s ruling to effectively terminate the border directive that has prevented the entry of millions of migrants.

The response on Tuesday from the Department of Justice comes a day after Chief Justice John Roberts issued a temporary stayof a federal district court judge’s order that required the Biden administration to lift the implementation of Title 42 by Wednesday morning.

Roberts’ order came in response to an emergency application filed by 19 Republican-led states to keep in place the Title 42 policy, a federal directive that has allowed border officials to “expel” millions of asylum-seeking migrants on public health grounds during both the Trump and Biden administrations. Roberts gave the Justice Department until Tuesday evening to respond while the high court decides whether to fulfill the states’ request for longer-term relief.

In its response, the Justice Department said it opposed the bid by the GOP-led states to keep the Title 42 limits in place while litigation over the issue proceeded. But at the same time, the federal government made a plea for additional time to prepare for a transition. The request comes as critics have been warning that the Biden administration was ill-prepared to handle an anticipated surge of migrants at the U.S.-Mexico border.

“The government recognizes that the end of the Title 42 orders will likely lead to disruption and a temporary increase in unlawful border crossings. The government in no way seeks to minimize the seriousness of that problem,” Solicitor General Elizabeth Prelogar wrote in the Tuesday afternoon submission. “But the solution to that immigration problem cannot be to extend indefinitely a public-health measure that all now acknowledge has outlived its public-health justification.”

Already, thousands of migrants appeared to have gathered along the southern border, knowing border officials will not be able to remove them as quickly as they could under the Title 42 restrictions first imposed by the Trump administration in March 2020 as the coronavirus began its global spread.

This week’s legal uncertainty over the fate of the border directive is yet another chapter in the Biden administration’s rocky journey in bringing to an end Trump-era immigration policies. Even as administration officials project preparedness, the situation at the southern border has become a political mess for the White House, and the request for additional time is yet another signal the administration is scrambling to implement a back-up plan to replace Title 42.

In Tuesday’s Supreme Court filing, the Justice Department conceded that the administration expected a temporary increase in border crossings, while asking that justices keep Title 42 in place at least until the end of the day on Dec. 27. And if the Supreme Court doesn’t reach a decision until Dec. 23 or later, the administration is asking for two business days to implement new policies.

Administration officials are still finalizing plans to deal with the impending surge, people familiar with the planning told POLITICO last week. DHS is weighing a revival of a “transit ban” model, ramping up new training for asylum officers to help them understand who qualifies under the international Convention Against Torture and considering an expansion of humanitarian parole programs for Haitians, Nicaraguans and Cubans.

“Although the end of the Title 42 orders likely will likely lead to a temporary increase in border crossings, the government is prepared to address that serious problem under its Title 8 authorities, including by adopting new policies to respond to the temporary disruption that will occur whenever the Title 42 orders end,” Prelogar said, alluding to the traditional immigration authorities the administration was expected to return to in handling — and limiting — asylum claims.

“If applicants are dissatisfied with the immigration system Congress has prescribed in Title 8, their remedy is to ask Congress to change the law — not to ask this Court to compel the government to continue relying on an extraordinary and now obsolete public-health measure as de facto immigration policy,” the solicitor general wrote.

The Supreme Court is expected to move quickly on the matter. A ruling that could have sweeping impacts at the border is likely to come within a matter of days.