Washington: President Donald Trump has moved to bar the majority of foreign students from entering the United States to study at Harvard University, in what marks the latest and most severe escalation in a long-running dispute between the White House and the prestigious Ivy League institution.

In an executive order signed on Wednesday, Trump claimed that permitting Harvard to continue hosting foreign students on its Cambridge, Massachusetts campus would compromise national security. The order directly targets the university’s international pipeline, which comprises roughly a quarter of its total student body and up to half in some graduate programmes.

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

The White House's decision follows a federal court ruling in Boston last week which blocked the Department of Homeland Security (DHS) from barring international students enrolled at Harvard. Trump’s order now relies on a different legal authority, signalling the administration’s determination to circumvent judicial resistance.

The dispute centres on a refusal by Harvard to fully comply with a series of federal demands. The administration claims the university has failed to provide adequate records related to alleged misconduct involving foreign students. Harvard maintains that it has responded appropriately to DHS requests, but the government says its cooperation has been “insufficient.”

Tensions between the Trump administration and Harvard have simmered for months, fuelled by allegations from federal officials that the university has become a "hotbed of liberalism" and is failing to address antisemitic incidents on campus. In response, Harvard has accused the administration of overreach, arguing that the demands violate the principle of academic autonomy and threaten the independence of all U.S. universities.

The executive order not only suspends the entry of new foreign students intending to enrol at Harvard but also places the status of current international students under review. Secretary of State Marco Rubio has been tasked with determining whether visas for existing students should be revoked.

The order is set to remain in effect for six months, with a review scheduled after 90 days to determine whether it should be extended. Exceptions may be made for students whose presence is deemed to “benefit the national interest,” though the criteria for such exemptions remain vague.

A State Department cable issued last week to U.S. embassies and consulates indicated that visa applicants associated with Harvard will now be subjected to heightened scrutiny, including reviews of their social media accounts for any signs of antisemitic content.

In a court filing, Harvard officials said the government’s actions have created an atmosphere of “profound fear, concern, and confusion” among international students. Maureen Martin, the university’s director of immigration services, noted that numerous students have inquired about transferring away from Harvard due to the uncertainty.