The requirement is part of new guidance from U.S. Immigration and Customs Enforcement, or ICE. The federal agency announced the measures on Monday. They provide additional pressure for universities to reopen as concern grows about the spread of COVID-19 among young adults.
Colleges learned of the rules the same day that some schools, including Harvard University, announced that all classes this autumn would be offered online.
U.S. President Donald Trump has urged schools and colleges to restart in-person classes as soon as possible. Soon after the guidance was released, Trump wrote on Twitter that schools must reopen this fall. He said Democratic Party lawmakers want to keep schools closed "for political reasons, not for health reasons."
U.S. immigration officials suspended some requirements for international students early in the pandemic. But colleges were waiting for guidance on what would happen in the fall. ICE told schools of the changes Monday, and said that official rules would be available soon.
Under the rules, international students must take at least some of their classes in person. New visas will not be given to students at schools or programs that are fully online. Even at colleges offering a mix of in-person and online classes, international students will be barred from taking all of their classes online.
The rules create an urgent problem for thousands of international students. Many became trapped in the United States last spring after the coronavirus forced their schools to move online.
International students who attend schools that are staying online must "depart the country or take other measures, such as transferring to a school with in-person instruction," ICE said.
The American Council on Education, which represents university presidents, described the guidelines as "horrifying."
An international student may have to leave the U.S. if their school experiences an outbreak and goes fully online after the fall term begins. It is not clear what would happen if a student was in such a situation but faced travel restrictions from their home country, said Terry Hartle, the council's senior vice president.
The international education group NAFSA also criticized the rules. It said school officials should be given the power to make decisions that are right for their own campuses. It said the guidance "is harmful to international students and puts their health and well-being and that of the entire higher education community at risk."
Nearly 400,000 foreigners received student visas in the 12-month period that ended on September 30, 2019. That number is down more than 40 percent from four years earlier. School administrations partly blame visa processing delays.
Colleges and universities across the U.S. were already expecting a sharp drop in international student numbers this fall. But losing all international students could be disastrous for some schools. Many depend heavily on tuition payments from international students, who often pay higher rates.
Critics of Trump sharply criticized the new guidance. Vermont Senator Bernie Sanders, an Independent, said the "cruelty of this White House knows no bounds."
"Foreign students are being threatened with a choice: risk your life going to class in-person or get deported," Sanders wrote on Twitter.
Many colleges have said they plan to offer at least some classes in person this fall, but some say it is too risky. Last week, the University of Southern California changed its plan to bring students to campus, with officials saying classes will instead be offered mostly online. On Monday, Harvard said it plans to invite only first-year students to live on its grounds. Its classes, however, will stay online.
I'm Ashley Thompson.