President Donald Trump’s administration has temporarily halted student visa interviews at U.S. embassies, as it considers expanding social media screening requirements for applicants.

Secretary of State Marco Rubio ordered diplomatic posts on Tuesday to pause applicant interviews for “any additional student or exchange visitor (F, M, and J) visa appointment capacity,” according to an internal cable obtained by Politico.

“Effective immediately, in preparation for an expansion of required social media screening and vetting, consular sections should not add any additional student or exchange visitor … visa appointment capacity until further guidance is issued [separate telegram], which we anticipate in the coming days,” the cable read.

Applicants could be subject to social media checks in the coming days, mimicking screening the Department of Homeland Security began recently to weed out “antisemitic activity on social media and the physical harassment of Jewish individuals.”

International students already admitted to American universities, who after receiving admission go through the student visa application process, will likely be affected by the move.

“We take very seriously the process of vetting who it is that comes into the country. And we’re going to continue to do that …  and again, whether they be student[s] or if you’re a tourist who needs a visa, or whoever you are, we’re going to be looking at you,” State Department spokeswoman Tammy Bruce said. “It seems to be such a controversial thing that’s going on, but it shouldn’t be, and every nation should take seriously, and does, who’s coming in. So if you’re going to be applying for a visa, follow the normal process, the normal steps, expect to be looked at and we go on from there.”

New vetting procedures could require consular officers to look for greater evidence of support for terrorist organizations on visa applicants’ social media pages.

Last week, Rubio told a Senate appropriations subcommittee that the State Department has revoked a number of visas that is “probably in the thousands at this point.”

“I don’t know the latest count, but we probably have more to do,” he added.

Last week, the Trump administration attempted to revoke Harvard University’s ability to enroll visa-carrying international students due to “pro-terrorist conduct” on campus. The effort was quickly, albeit temporarily, blocked by a federal judge when Harvard sued the Trump administration.