On Monday, Immigration and Customs Enforcement officials announced that international students taking courses at entirely online schools this fall will not be allowed to enter the country and, if they are already here, must leave. The agency suggested that international students who want to stay in the U.S. should transfer to a school offering in-person courses in the fall, or they risk deportation.

In the wake of the coronavirus pandemic, many schools — Harvard and Princeton among them — are opting to move their entire course offering online in order to observe social distancing guidelines recommended by the CDC. Prior federal regulations only let international students take three credit hours online, and the Department of Homeland Security’s Student and Exchange Visitor Program had previously issued temporary exceptions for schools going online due to COVID-19. But an ICE spokesperson told Buzzfeed News that while the agency “has been trying to be flexible in the accommodations it was making but needed to make sure we were maintaining oversight with international students.”

“This was the best way of doing so,” they added.

Some critics accused ICE of leveraging the pandemic to reduce the number of immigrants in the U.S. — a long time goal of the Trump administration. Harvard President Larry Bacow told Buzzfeed that the agency was using too-broad of a policy for a complicated issue.

“We will work closely with other colleges and universities around the country to chart a path forward” Bacow said. “We must do all that we can to ensure that our students can continue their studies without fear of being forced to leave the country mid-way through the year, disrupting their academic progress and undermining the commitments—and sacrifices—that many of them have made to advance their education.”

There were also concerns that the new ICE policy may force some schools to offer in-person classes despite the pandemic in order to keep from losing tuition money from international students, particularly in science and engineering departments where natural-born American citizens are not enrolling in sufficient numbers to maintain financial feasibility.