President Donald Trump signed a proclamation to suspend international visas for new students at Harvard University, the White House announced Wednesday, in a dramatic escalation of its efforts to block foreigners from enrolling at the elite university.

The move to limit student visas at Harvard comes days after a judge blocked the Trump administration’s attempts to revoke the school’s ability to host foreign students.

US Secretary of State Marco Rubio would review on a case by case basis the visa status of existing Harvard students to determine whether their status should be revoked.