International students will be forced to leave the US or move to other colleges if their school offers classes entirely online this fall, under new guidelines issued Monday by federal immigration authorities.

The guidelines, issued by US Customs Immigration and Enforcement, provide additional pressure for universities to reopen even amid growing concerns about the recent spread of COVID-19 among young adults. The college received guidance on the same day that several institutions, including Harvard University, announced that all instructions would be offered remotely.

President Donald Trump urged schools and colleges to return to direct teaching as soon as possible. Shortly after the guide was released, Trump repeated on Twitter that schools had to reopen this fall, adding that Democrats wanted to make schools closed “for political reasons, not for health reasons.”

“They think it will help them in November. Wrong, people understand! “Trump writes.

Under the updated rules, international students must take at least some of their classes directly. New visas will not be given to students in schools or programs that are fully online. And even in colleges that offer a mix of private and online courses this fall, international students will be barred from taking all their classes online.

This created an urgent dilemma for thousands of international students who were stranded in the US last spring after coronavirus forced their schools to move online. Those who attend schools that remain online must “leave the country or take other actions, such as transferring to schools with direct instruction,” according to the guidelines.

The American Council on Education, which represents the university president, said the guidelines were “terrible” and would cause confusion when schools looked for ways to reopen safely.

Of particular concern are provisions which say that students will not be exempt from regulations even if an outbreak forces their schools online during the fall. It is not clear what will happen if a student ends up in that scenario but faces travel restrictions from their home country, said Terry Hartle, senior council vice president.

“That will cause tremendous confusion and uncertainty,” Hartle said. “ICE clearly creates incentives for institutions to reopen, regardless of whether a pandemic is needed or not.”

The NAFSA international education group condemned the regulations and said schools must be given the authority to make the right decisions for their own campus. The guidelines said it was “dangerous for international students and endangering the health and well-being of them and the entire tertiary education community.”

Nearly 400,000 foreigners received student visas in the 12-month period ending September 30, down more than 40% from the previous four years. The school administration partly blames the visa processing delay.

Colleges across the US are already expecting a sharp drop in international registration this fall, but losing all international students can be a disaster for some. Many depend on income from tuition fees from international students, who usually pay a higher level of tuition. Last year, US universities attracted nearly 1.1 million students from abroad.

Trump’s critics quickly attacked the new guidelines. Senator Bernie Sanders, an independent Vermont, said “this White House cruelty knows no bounds.”

“Foreign students are threatened with choices: the risk of your life going to class directly or being deported,” Sanders said in a tweet. “We must support Trump fanaticism. We must keep all our students safe. “

Dozens of colleges say they plan to offer at least a few classes directly this fall, but some say it’s too risky. The University of Southern California last week turned its back on plans to bring students to campus, saying classes will be held primarily or online. Harvard on Monday said it would invite first-year students to live on campus, but the class would remain online.

Immigration authorities deferred certain requirements for international students at the start of the pandemic, but colleges are waiting for guidance on what will happen this fall. ICE notified schools about the change on Monday and said there would be formal rules.

The announcement was a strike related to Trump’s latest pandemic administration to legal immigration. Last month, authorities extended a new green card ban for many people outside the United States and expanded the freeze to include many temporary work permits, including in high-tech companies, multinational companies and seasonal employers.

Administrations have long sought deep cuts for legal immigration, but their goals are difficult to understand before the corona virus.