(CNN) - International students who are pursuing degrees in the United States will have to leave the country or risk deportation if their universities switch to online-only courses, Immigration and Customs Enforcement announced Monday.

The move may affect thousands of foreign students who come to the United States to attend universities or participate in training programs, as well as non-academic or vocational studies.

Universities nationwide are beginning to make the decision to transition to online courses as a result of the coronavirus pandemic. At Harvard, for example, all course instruction will be delivered online, including for students living on campus. For international students, that opens the door to them having to leave the US.

In a news release Monday, ICE said that students who fall under certain visas "may not take a full online course load and remain in the United States," adding, "The U.S. Department of State will not issue visas to students enrolled in schools and/or programs that are fully online for the fall semester nor will U.S. Customs and Border Protection permit these students to enter the United States."

The agency suggested that students currently enrolled in the US consider other measures, like transferring to schools with in-person instruction. There's an exception for universities using a hybrid model, such as a mix of online and in-person classes.

Visa requirements for students have always been strict and coming to the US to take online-only courses has been prohibited.

"These are not some fly-by-night universities, these aren't scams, these are legit universities who would normally have in-person curricula but for coronavirus," said Theresa Cardinal Brown, director of immigration and cross-border policy at the Bipartisan Policy Center. 

"The bigger issue is some of these countries have travel restrictions on and they can't go home, so what do they do then?" she added. "It's a conundrum for a lot of students."

https://www.cnn.com/2020/07/06/politics/international-college-students-ice-online-learning/index.html