The State Department has halted the scheduling of new visa interviews for foreign students hoping to study in the U.S. while it prepares to expand the screening of their activity on social media, officials said.

A U.S. official said Tuesday the suspension is intended to be temporary and does not apply to applicants who already had scheduled their visa interviews. The official spoke on condition of anonymity to discuss an internal administration document.

A cable signed by Secretary of State Marco Rubio and obtained by The Associated Press says the State Department plans to issue guidance on expanded social media vetting.

“Effective immediately, in preparation for an expansion of required social media screening and vetting, consulate sections should not add any additional student or exchange visitor visa appointment capacity” until the guidance is issued, the cable says.

Asked about the suspension at a briefing Tuesday, State Department spokesperson Tammy Bruce said the U.S. uses every available resource to vet people applying for visas.

“We will continue to use every tool we can to assess who it is that’s coming here, whether they are students or otherwise,” Bruce said. The move, first reported by Politico, is the latest in the Trump administration’s crackdown on international students.

Last week, the Trump administration revoked Harvard University’s ability to enroll international students, removing the college from the program that allows schools to sponsor foreign students for visas. That effort was quickly challenged in court and for now is blocked by a federal judge.

This spring the administration also revoked the legal status of thousands of international students already in the country, leading some to leave the U.S. out of fear of deportation. After many students filed successful legal challenges, the administration said it was restoring the students’ legal status. But the government also expanded the grounds for terminating international students’ legal status going forward.

President Donald Trump’s previous administration stepped up scrutiny of all visa applicants, introducing reviews of their social media accounts. The policy remained during President Joe Biden’s administration.

An extended pause in scheduling student visas could lead to delays that may disrupt college, boarding-school or exchange students’ plans to enroll in summer and fall terms. A downturn in enrollment of international students could hurt university budgets. To make up for cuts in federal research funding, some colleges shifted to enrolling more international students, who often pay full tuition.