International students will be required to take at least one in-person class to keep their visas, at a time when many universities are prioritizing online instruction.

International students whose universities are not planning in-person classes — which is currently the case at schools including the University of Southern California and Harvard — would be required to return to their home countries if they are already in the United States.

Cuccinelli II, the acting deputy secretary of the Department of Homeland Security, said in an interview on CNN that the administration was providing more flexibility for international students than in the past, when they could only take one online course to qualify for visas.

To maintain their status, many international students raced this week to enroll in in-person classes, even if they were not connected to their majors, and students at nearly a dozen universities started an online spreadsheet so that American students could try to swap in-person course spots with their foreign classmates.

Loay Alem, 19, an engineering student from Saudi Arabia, said he had put down a $1,000 security deposit on an apartment for the fall, enrolled in several online courses and paid tuition at U.C.L.A., which had about 5,800 international students last academic year.

Rosemary Jenks, the director of government relations for NumbersUSA, a group that lobbies for fewer immigrants in the United States, said that by forcing international students to leave the country, the new rule could help close a pipeline of students who obtain authorization to temporarily work in the United States for 12 months after graduation.

The United States has long attracted a bevy of international students, and in recent years they have become a key source of funding for both private and state colleges and universities, as many have struggled with reduced U.S.

More than a million international students were issued visas to study in the United States last year.

In March, as the coronavirus outbreak forced universities to abruptly close their campuses, the Trump administration offered those students flexibility, allowing them to remain legally in the United States, said Dan Berger, a lawyer who specializes in academic immigration.

If students attending universities with online classes wish to remain in the country, they will have to transfer to an institution that offers in-person courses, which is virtually impossible given the short notice.

At the University of Arizona, where nearly 4,000 international students were enrolled last academic year, Brent White, the vice provost for global affairs, said the school would ensure that such students are all able to take in-person classes and remain in the United States.

“Even if the circumstances due to Covid-19 are that most people have to be online,” he said, “we have enough space that we think we can accommodate requirements that international students have in-person participation.”.

“After 14 years of living in the United States, my native country is foreign to me,” she said