Border Patrol agents apprehended over 10,000 migrants on both Monday and Tuesday, Customs and Border Protection (CBP) sources tell Fox News, marking the highest single-day totals ever recorded ahead of the end of the Title 42 public health order later this week.

Sources say agents apprehended at least 10,300 migrants who crossed illegally on Tuesday, in addition to the over 10,000 encountered on Monday. There are currently 28,500 migrants in custody.

Fox is told that the numbers are expected to keep increasing ahead of the end of the Title 42 order on Thursday. Officials have been preparing for months for an expected surge in migration across the border once the order ends. The order has been used since March 2020 by both the Trump and Biden administrations to expel hundreds of thousands of migrants quickly due to the COVID-19 pandemic. In March, nearly half of all migrant encounters ended in a Title 42 expulsion. 

BIDEN ADMIN TALKS ‘TOUGHER’ ON BORDER AHEAD OF TITLE 42'S END — BUT MIGRANTS AREN'T LISTENING

Officials and lawmakers have feared that migrants, believing they are more likely to be admitted to the U.S. once the order ends, will head to the border in numbers not even seen during the more than two-year migrant crisis so far. Officials had previously painted a worst-case scenario of up to 14,000 encounters a day. 

Migrants have been surging into border areas like Brownsville and El Paso, Texas, where thousands of migrants were camped out on the streets. Officials later launched a targeted enforcement operation to handle the increase, where pamphlets were given to migrants to urge them to head to nearby processing centers.

The administration has been urging migrants not to make the journey north, claiming they will be removed if they enter illegally — but so far it does not appear to be acting as a deterrent.

"To the individuals themselves, who are thinking of migrating: Do not believe the smugglers," Department of Homeland Security (DHS) Secretary Alejandro Mayorkas said Friday. "Because you are being deceived, and you are risking your lives and your life savings only to meet a consequence that you do not expect at our southern border."

A U.S. Border Patrol agent talks with asylum-seekers

A U.S. Border Patrol agent talks with asylum-seekers waiting between the double fence along the U.S.-Mexico border near Tijuana, Mexico, in San Diego on Monday. The migrants wait between the fences to be processed by U.S. Border Patrol agents.  (AP Photo/Denis Poroy)

The administration has sent personnel including troops to the border, and has said it is stiffening penalties for illegal entry once Title 42 ends. It is also rolling out a new asylum rule that would technically make migrants ineligible for asylum if they have crossed illegally and failed to claim asylum in a country through which they have previously traveled. It is also creating processing centers across Latin America to screen migrants to see if they are eligible for a variety of lawful pathways into the U.S. or other participating countries.

BORDER PATROL CLEARS WAY FOR MORE MIGRANT RELEASES TO CITY STREETS, SOURCES SAY

It has also secured agreements with Mexico to accept non-Mexican migrants and to ramp up enforcement at its own southern border to stop migrants traveling through to the U.S. But President Biden, even when hailing those agreements, admitted on Tuesday that it is going to be "chaotic for a while" once the order ends.

Republicans have blamed the administration for abandoning Trump-era border policies, such as wall construction and the Remain-in-Mexico policy, that they say were working to bring numbers down. They attribute the crisis to an increase of "catch-and-release" combined with reduced interior enforcement under the Biden administration.

MAYORKAS PLEADS WITH MIGRANTS NOT TO ENTER US ILLEGALLY WHEN TITLE 42 ENDS

The administration has pushed back, arguing that Republicans need to provide more funding for CBP and to back an immigration reform bill that Democrats introduced in 2021 that would expand legal pathways while granting a mass amnesty to millions of illegal immigrants already in the U.S. Republicans have refused to consider any form of citizenship pathway until the border is secure, and Republicans in the House have recently introduced a border and immigration package of their own — the administration has rejected it.

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Meanwhile, Fox reported Tuesday that top border officials have decided to authorize all Border Sectors to begin "safe" mass releases of migrants to city streets if NGOs do not have the room to hold them. The consequence of this decision is that migrants will be mass released at bus stops, gas stations, supermarkets and in towns and cities across the border as Customs and Border Protection facilities are already over capacity in multiple sectors, sources said.

"The dam is about to break," one Border Patrol source said.