Foreign students are not allowed to stay in America this autumn, unless they switch to the course with personal tuition, if their universities have moved classes fully online.
The ICE agency said people could face expulsions if they do not comply with rules. The ICE agency said people could face expulsion.
Since of the coronavirus pandemic, many colleges switch online classes.
The number of students affected is not clear.
A large number of foreign students visit the US every year and provide as many universities with full tuition, an important source of revenue.
As students return for their new academic year, including university residents Harvard announced that all course instruction would be provided online.
The ICE Student and Exchange Visitor Program allowed international students to continue their online courses in spring and summer 2020 while staying in the country.
But the announcement from Monday said that foreign students who remain in the United States while studying online and failing to transfer to one-to-one courses would face "immigration implications," including the opening of removal proceedings, but not limited to.
To F-1 and M-1 visa holders to undergraduate and technical students. The law applies. According to the agency's reports, in fiscal 2019 the State Department provided 388,839 F visas and 9,518 M visas.
Foreign students contributed $45 billion ( £ 36 billion) to the economy in 2018, according to the U.S. Department of Commerce.