The Trump administration has ordered U.S. embassies to halt new student visa appointments as it plans to expand social media vetting for applicants. In a memo, Secretary of State Marco Rubio said the pause would remain in place “until further guidance is issued.” Existing appointments can proceed, but unfilled ones must be removed.

The new policy focuses on student and exchange visas and could significantly affect embassy operations. The move comes amid Trump’s criticism of elite U.S. universities, accusing them of promoting anti-Semitism and enforcing discriminatory admissions.

The State Department said it’s intensifying vetting processes to better screen those entering the country. Meanwhile, courts have blocked several Trump efforts to cut university funding, deport students, and revoke visas. Harvard, a primary target, recently had its ability to host foreign students and researchers revoked, but a judge halted the decision. The measure, if upheld, could severely impact the university, where over 25% of students are international.