After three years of using a pandemic-era rule known as Title 42 to control the flow of migrants at the U.S.-Mexico border, the Biden administration is preparing for its end. In recent days, it has rolled out several new immigration rules meant to discourage migrants from coming to the border.

Those who do not use legal pathways to come to the United States — including securing an asylum appointment using a smartphone application — will face harsher consequences, including removal and a five-year ban from reentering. Among the other pathways the administration has made available is a two-year humanitarian parole program for nationals of Cuba, Haiti, Nicaragua and Venezuela. More than 100,000 people have arrived lawfully in the U.S. through the program, Department of Homeland Secretary Alejandro Mayorkas said Wednesday.

More than 665,000 people have already been expelled or removed from the U.S. since October and the administration continues to operate dozens of deportation flights, Mayorkas said. Smugglers, he noted, have been hard at work spreading false information that the U.S.-Mexico border will be open after Thursday.

“It will not be,” Mayorkas said. “To people who are thinking of making the journey to our southern border know this: The smugglers care only about profit, not people. They do not care about your or your well-being.”

On Wednesday, the administration also announced it was finalizing a new asylum rule requiring migrants to first seek protection in a country they transited through before arriving at the U.S.-Mexico border.

Here is what you should know about Title 42 and the coming changes:

What is Title 42?

In March 2020, as the COVID-19 pandemic began to spread in the United States, the U.S. Centers for Disease Control and Prevention issued Title 42 to limit migration, saying it was necessary to reduce the spread of the disease. The CDC has the authority to do this under the Public Health Service Act of 1944.

Under Title 42, the Trump administration authorized Customs and Border Protection to immediately expel migrants who crossed into the United States without proper documentation, including those seeking asylum.

The Biden administration continued the policy at first, but said it would push to end it. The policy was initially upheld in federal court after Republican-leaning states sued to keep it in place.

How does it work?

Title 42 lets border agents to quickly expel migrants, including those seeking asylum who arrive at the U.S.-Mexico border. Under the rule, immigration officials can take as little as 10 minutes to process migrants and expel them either back to Mexico or their home country.

Since Title 42 began to be enforced, it has been used to remove more than 2.8 million times to expel migrants, although children traveling alone have been exempt.

What is changing?

The order will end at 11:59 p.m. Thursday. The Biden administration announced in January that it was ending the national emergencies linked to the COVID-19 pandemic. That also spelled the end of using Title 42 to control immigration at the border.

What will happen next?

With the end of Title 42, migrants will find tougher immigration enforcement under the regulation known as Title 8. Migrants will be given the option of voluntarily returning to the country from which they came. If they refuse, they will be expelled — and be subjected to at least a five-year ban on admission and potential criminal prosecution should they seek to reenter unlawfully, immigration officials have warned.

In some cases, they will be deported to their home country, and in others back to Mexico, under an agreement with the Mexican government.

Deportations and a ban on re-entering the U.S. will also apply to those who attempt to cross by sea through the Florida Straits or Puerto Rico’s Mona Passage. For Haitian and Cuban migrants, this will also make them ineligible to participate in a two-year humanitarian parole program the Biden administration launched in January, which allows legal entry into the U.S. for them if they have a U.S. sponsor and a valid passport.

How can migrants get to the United States after Title 42 ends?

The Biden administration has announced an expansion of several new legal pathways for migrants. In January, the administration launched a humanitarian parole program for migrants from Cuba, Haiti and Nicaragua. Already provided to Venezuelan nationals, the program allows 30,000 individuals a month from the four countries combined to legally fly to the U.S. if they have a U.S. sponsor and a valid passport.

The administration has also said it will launch regional processing centers in Central and South America to process asylum seekers, who must now seek pre-authorization using a smartphone application, CBP One, to reserve asylum appointments.

What if migrant shows up at the border without permission?

U.S. law will presume that any individual who does not use a lawful pathway to enter the United States is ineligible for asylum. A new rule being finalized by the Department of Homeland Security and the Department of Justice will allow the United States to remove individuals who do not establish a reasonable fear of persecution. The rule goes into effect after Title 42 ends.

How have migrants reacted?

Migrants from several countries have massed at the U.S.-Mexico border, hoping to beat Thursday’s deadline and tougher immigration enforcement that could bar re-entry or a chance to apply for asylum for five years.

In recent days, advocates working with migrants from Venezuela and Haiti have warning migrants seeking to reach the border that it isn’t open and they face expulsion from the United States. But many of their efforts have fallen on deaf ears.

For example, migrants who have made their way into Juárez, across the border from El Paso, Texas, are camping or lining up in informal areas hoping to cross into the U.S. ahead of the expiration.

“As we have said repeatedly, individuals who do not have a lawful basis to remain will be removed,” Customs and Border Protection Acting Commissioner Troy Miller said about migrants gathered on the U.S. side. “Individuals should not listen to the lies of smugglers and instead use lawful pathways to protection.”

The U.S. recently dispatched 1,500 active-duty troops to the border to join 2,500 National Guards already there.

“The border is not open, it has not been open, and it will not be open subsequent to May 11,” Homeland Security Secretary Alejandro Mayorkas said last week.

Read more: New program for Cuban, Haitian and Nicaraguan migrants is complex. What you need to know

How is the U.S. getting the news to migrants?

On Wednesday, the U.S. launched a new digital advertising campaign in South and Central America to counter the lies of smugglers with “accurate U.S. immigration laws,” Mayorkas said.

Miami Herald wire services were used in compiling this report.