WASHINGTON — Citing the threat of the coronavirus to the American public, the Trump administration said on Friday it will begin rapidly sending foreigners who illegally cross the United States borders to their home countries and halt the processing of undocumented migrants at ports of entry.
Chad Wolf, the acting secretary of homeland security, said the United States will also close the legal entry points along the border with Mexico and Canada to tourism. American citizens, lawful permanent residents, and those crossing a border to seek medical treatment or attend educational institutions would not be affected. Commercial traffic would remain open, but port officers would stop processing those without legal authority to be in the United States, including migrants seeking asylum.
Mr. Wolf said the Centers for Disease Control and Prevention had issued the order to turn away any people who cross the southwestern border illegally instead of bringing them to a detention center where they could ask for asylum in the United States. President Trump has sought such a restrictive policy for years, but the courts have blocked it as a violation of due process.
“We’re trying to limit the amount of contact we have with these individuals,” said Mr. Wolf, adding that many migrants who cross the border often lack documents to prove their medical history. “It’s going to be very rapid.”
Under the new rule, set to take effect Saturday, Border Patrol agents will be issued biometric tools to process migrants in the field. Migrants that have a criminal history will still be detained, but agents are being directed to take others to the nearest port of entry or airfield, where they are to be returned to their home countries. Unaccompanied children would be exempt from the rule, a Customs and Border Protection official said.
Mr. Trump said earlier this week that his administration would begin immediately turning away migrants, as well as asylum seekers, using authorities granted to the U.S. surgeon general. On Friday, he made it official.
“Our nation’s top health care officials are extremely concerned about the public health consequences of mass, uncontrolled cross-border movement,” Mr. Trump said. “That would be mostly, but even beyond, but mostly during this global pandemic.”
He deputized his top health officials on Friday as de facto spokesmen for his hard-line border policy.
Alex M. Azar II, the secretary of health and human services, said, “a number of health challenges arise when illegal immigrants arrive at our northern and southern borders.”
“When held at border facilities, these migrants were spreading the virus to other migrants, to C.B.P. agents and border health care workers and even the United States population as a whole,” said Mr. Azar, referring to Customs and Border Protection.
The rule will be in effect for up to a year, or until Mr. Azar determines it is no longer necessary, according to a Health and Human Services regulation published on Friday.
As of Friday evening, Mexico had confirmed 164 cases of coronavirus, as the United States soared over 16,600. Guatemala, El Salvador and Honduras, the so-called Northern Triangle of Central America, where many migrants are from, had 37.
When asked if any detained migrants were confirmed to have the coronavirus, John Mennell, a spokesman for Customs and Border Protection, only said “this is exactly what we are trying to prevent.”
Migrant detention facilities have been criticized in the past for their poor conditions. Last year, many migrant children fell ill in the crowded and cramped facilities.
Whether the policy can be implemented remains to be seen.
A border patrol official said agents still had not received new guidance on the rule, despite it taking effect at midnight. It was also unclear whether agents would prevent every migrant who crossed illegally from asking for asylum in the United States before immediately returning them.
Two border patrol officials said the understanding among agents was to evaluate each illegal crosser on a “case-by-case basis,” while Mr. Trump and Mr. Wolf said all foreigners who illegally cross would be immediately be sent back.
Administration officials also initially said the rule would entail returning every foreigner that crossed the border illegally to Mexico. But the Mexican government, which was blindsided when Mr. Trump confirmed the plan earlier this week, has since then said it would not accept all returned migrants.
“If they return people who are neither Mexican nor Central Americans, Mexico would not accept it,” Marcelo Ebrard, Mexico’s foreign minister, said. Central American migrants are sent to Mexico from the United States under a different policy, one that allows them to make an asylum claim but forces them to wait on the Mexican side of the border while the case is adjudicated.
After Mr. Ebrard stated Mexico’s position in a separate briefing, Mr. Wolf said migrants from countries other than Mexico would be taken to airfields, where flights chartered by Immigration and Customs Enforcement routinely deport migrants.
While the administration is already diverting asylum seekers to Guatemala, it is unclear if the agency is prepared to return every foreigner to their home country. Mr. Wolf said the Department of Homeland Security is currently apprehending migrants from more than 120 countries. Coordinating such transports with the government of a migrant’s home country and securing them space on a flight would likely require holding them for at least a short period of time.
In the past, the department has been able to return migrants to Mexico by asking them if they would voluntarily go home, according to Theresa Cardinal Brown, the director of immigration and cross-border policy at the Bipartisan Policy Center. But in those cases, migrants could opt out of that process and express a need for asylum.
She said the administration’s new rule, citing authority granted to top health officials in the United States, would conflict with the immigration law that permits migrants on U.S. soil, even those who had crossed illegally, to start the asylum process.
“I’ve never seen this happen yet, so we have to see how this works in practice,” Ms. Brown said. “You’re faced with a conflict. A conflict of denying entry for health reasons and a right to apply for asylum.”
Zolan Kanno-Youngs reported from Washington and Kirk Semple from Mexico City.