“Do not, do not just show up at the border,” Biden said as he announced the changes, even as he acknowledged the hardships that lead many families to make the dangerous journey north.

“Stay where you are and apply legally from there,” he advised.

Biden made the announcement just days before a planned visit to El Paso, Texas, on Sunday for his first trip to the southern border as president. From there, he will travel on to Mexico City to meet with North American leaders on Monday and Tuesday.

Homeland Security officials said they would begin denying asylum to those who circumvent legal pathways and do not first ask for asylum in the country they traveled through en route to the U.S.

Instead, the U.S. will accept 30,000 people per month from the four nations for two years and offer the ability to work legally, as long as they come legally, have eligible sponsors and pass vetting and background checks. Border crossings by migrants from those four nations have risen most sharply, with no easy way to quickly return them to their home countries.

“This new process is orderly,” Biden said. “It’s safe and humane, and it works.”

The move, while not unexpected, drew swift criticism from asylum and immigration advocates, who have had a rocky relationship with the president.

“President Biden correctly recognized today that seeking asylum is a legal right and spoke sympathetically about people fleeing persecution,” said Jonathan Blazer, the American Civil Liberties Union’s director of border strategies. “But the plan he announced further ties his administration to the poisonous anti-immigrant policies of the Trump era instead of restoring fair access to asylum protections.”

Even with the health law restrictions in place, the president has seen the numbers of migrants crossing the U.S.-Mexico border rise dramatically during his two years in office; there were more than 2.38 million stops during the fiscal year that ended Sept. 30, the first time the number topped 2 million. The administration has struggled to clamp down on crossings, reluctant to take hard-line measures that would resemble those of the Trump administration.

That’s resulted in relentless criticism from Republicans who say the Democratic president is ineffective on border security, and the newly minted Republican House majority has promised congressional investigations on the matter.

The new policy could result in 360,000 people from these four nations lawfully entering the U.S. in a year, a huge number. But far more people from those countries have been attempting to cross into the U.S. on foot, by boat or swimming; migrants from those four countries were stopped 82,286 times in November alone.

Enyer Valbuena, a Venezuelan who was living in Tijuana, Mexico, after crossing the border illegally, said Thursday’s announcement came as no surprise but a blow nonetheless.

“This was coming. It’s getting more difficult all the time,” he said by text message.

Mexico has agreed to accept up to 30,000 migrants each month from the four countries who attempt to walk or swim across the U.S.-Mexico border and are turned back. Normally, these migrants would be returned to their country of origin, but the U.S. cannot easily send back people from those four countries for a variety of reasons that include relations with the governments there.

Anyone coming to the U.S. is allowed to claim asylum, regardless of how they crossed the border, and migrants seeking a better life in the U.S. often pay smugglers the equivalent of thousands of dollars to deliver them across the dangerous Darien Gap.