Donald Trump signed a proclamation to restrict foreign student visas at Harvard University, the White House said, writes The Guardian.

The order would suspend for an initial six months the entry into the US of foreign nationals seeking to study or participate in exchange programs at Harvard. Trump declared that it would jeopardize national security to allow Harvard to continue hosting foreign students.

The proclamation is the US president’s latest attempt to choke the Ivy League school from an international pipeline that accounts for a quarter of the student body, and a further escalation in the White House’s fight with the institution.

“I have determined that the entry of the class of foreign nationals described above is detrimental to the interests of the United States because, in my judgment, Harvard’s conduct has rendered it an unsuitable destination for foreign students and researchers”, - Trump wrote in the order.

Trump’s proclamation also directs the US state department to consider revoking academic or exchange visas of any current Harvard students who meet his proclamation’s criteria.

Harvard in a statement called Trump’s proclamation “yet another illegal retaliatory step taken by the Administration in violation of Harvard’s First Amendment rights”. “Harvard will continue to protect its international students”.

Trump singled out Harvard’s connections with China as reason for cutting off the university from foreign students. The proclamation said Harvard was linked to research that “could advance China’s military modernisation”.