President Donald Trump has 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 foreign nationals from enrolling at the elite university.

President Donald Trump has escalated his standoff with Harvard University, seeking another path to prevent international students from attending the school after a judge blocked an attempt to revoke Harvard’s ability to enroll international students.

Trump's proclamation cited national security concerns as a justification for barring international students from entering the United States to pursue studies at the Cambridge, Massachusetts-based university.