Asylum seekers hoping to enter the United States will be required to wait in Mexico while their claims are processed, according to a new deal reportedly struck between the Trump administration and Mexico’s incoming government.

Quoting senior members of President-elect Andrés Manuel López Obrador’s team, the Washington Post reports that while a formal agreement has yet to be signed, the “Remain in Mexico” plan will prevent those seeking asylum from stepping onto U.S. soil until their applications are approved.

The deal marks a dramatic change in government policy, which currently allows those seeking asylum to remain in the U.S. while awaiting the decisions on their applications.

ASSOCIATED PRESS Seven-year-old Honduran migrant Genesis Belen Mejia Flores waves an American flag at two U.S. border control helicopters flying overhead near a shelter in Tijuana, Mexico.

However, as HuffPost previously reported, it’s unclear if the “Remain in Mexico” plan would survive a court challenge.

Lee Gerlent, an attorney with the American Civil Liberties Union, told the Post that while it was too early to comment on potential litigation, the government “ought to concentrate on providing a fair and lawful asylum process in the U.S. rather than inventing more and more ways to try and short-circuit it.”

President Donald Trump seemed to confirm the report in a series of tweets Saturday evening.

“Migrants at the Southern Border will not be allowed into the United States until their claims are individually approved in court,” he wrote. “We only will allow those who come into our Country legally. Other than that our very strong policy is Catch and Detain. No ‘Releasing’ into the U.S.”

Migrants at the Southern Border will not be allowed into the United States until their claims are individually approved in court. We only will allow those who come into our Country legally. Other than that our very strong policy is Catch and Detain. No “Releasing” into the U.S... — Donald J. Trump (@realDonaldTrump) November 24, 2018

....All will stay in Mexico. If for any reason it becomes necessary, we will CLOSE our Southern Border. There is no way that the United States will, after decades of abuse, put up with this costly and dangerous situation anymore! — Donald J. Trump (@realDonaldTrump) November 24, 2018

Earlier Saturday, Mexico’s incoming Interior Minister, Olga Sánchez Cordero, told Reuters that there were no plans for the country to host asylum seekers.

“The future government does not consider ... that Mexico assumes the status of ‘safe third country’ for Central American migrants, or from other countries, who are on Mexican territory or for those who will reach it in the future,” she said in a statement.

But in an interview with the Post, Sánchez Cordero said that the incoming government had “agreed to this policy of Remain in Mexico,” referring to it as a “short-term solution.”

“The medium- and long-term solution is that people don’t migrate,” she said. “Mexico has open arms and everything, but imagine, one caravan after another, that would also be a problem for us.”

Lucy Nicholson / Reuters Members of a caravan from Central America trying to reach the United States sleep under a road bridge next to the U.S.-Mexico border in Tijuana, Mexico.

News of the deal comes after Trump repeatedly castigated a migrant caravan making its way to the U.S.-Mexico border from Central America.

The president painted those traveling in the group as criminals and went so far as to announce that he had authorized troops to use “lethal force” against them.

Several thousand members of the caravan who have already arrived in the border city of Tijuana are in a state of limbo as they await their fate in makeshift migrant shelters. According to The New York Times, officials expect at least 1,500 more people will arrive in the coming days.

ASSOCIATED PRESS U.S. Customs and Border Protection agents stand guard at the San Ysidro port of entry on the U.S.-Mexico border, seen from Tijuana, Mexico.

Last week, Trump tweeted that the U.S. was “ill-prepared for this invasion, and will not stand for it” before hinting at the new policy.

“Catch and Release is an obsolete term. It is now Catch and Detain. Illegal Immigrants trying to come into the U.S.A., often proudly flying the flag of their nation as they ask for U.S. Asylum will be detained or turned away.”

The Mayor of Tijuana, Mexico, just stated that “the City is ill-prepared to handle this many migrants, the backlog could last 6 months.” Likewise, the U.S. is ill-prepared for this invasion, and will not stand for it. They are causing crime and big problems in Mexico. Go home! — Donald J. Trump (@realDonaldTrump) November 18, 2018

Catch and Release is an obsolete term. It is now Catch and Detain. Illegal Immigrants trying to come into the U.S.A., often proudly flying the flag of their nation as they ask for U.S. Asylum, will be detained or turned away. Dems must approve Border Security & Wall NOW! — Donald J. Trump (@realDonaldTrump) November 18, 2018