Boston, Massachusetts - A court on Thursday put a temporary stay on Donald Trump's latest effort to stop international students from enrolling at Harvard, as the president's attacks on one of the world's most prestigious universities intensified.

A proclamation issued by the White House late Wednesday sought to bar most new international students at Harvard from entering the country, and said existing foreign enrollees risked having their visas terminated.

"Harvard's conduct has rendered it an unsuitable destination for foreign students and researchers," the order said.

Harvard quickly amended an existing complaint filed in federal court, saying: "This is not the Administration's first attempt to sever Harvard from its international students."

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"(It) is part of a concerted and escalating campaign of retaliation by the government in clear retribution for Harvard's exercising its First Amendment rights to reject the government's demands to control Harvard's governance, curriculum, and the 'ideology' of its faculty and students."

US District Judge Allison Burroughs on Thursday ruled the government cannot enforce Trump’s proclamation.

Harvard had showed, she said, that without a temporary restraining order, it risked sustaining "immediate and irreparable injury before there is an opportunity to hear from all parties."

The same judge had already blocked Trump's earlier effort to bar international students from enrolling at the storied university.

The government already cut around $3.2 billion of federal grants and contracts benefiting Harvard and pledged to exclude the Cambridge, Massachusetts, institution from any future federal funding.

Harvard has been at the forefront of Trump's campaign against top universities after it defied his calls to submit to oversight of its curriculum, staffing, student recruitment, and "viewpoint diversity."

Trump has also singled out international students at Harvard, who accounted for 27% of total enrollment in the 2024-2025 academic year and are a major source of income.

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In its filing, Harvard acknowledged that Trump had the authority to bar an entire class of noncitizens if it was deemed to be in the public interest, but stressed that was not the case in this action.

"The President's actions thus are not undertaken to protect the 'interests of the United States' but instead to pursue a government vendetta against Harvard," it said.

Since returning to office Trump has targeted elite US universities which he and his allies accuse of being hotbeds of antisemitism, liberal bias, and "woke" ideology. In particular, he has attempted to shut down the Palestine solidarity movement on university campuses, and targeted noncitizen students for deportation who have taken a stand for human rights.

Trump's education secretary also threatened on Wednesday to strip Columbia University of its accreditation. The Republican has targeted the New York Ivy League institution for allegedly ignoring harassment of Jewish students, throwing all of its federal funding into doubt.

Unlike Harvard, several top institutions – including Columbia – have already bowed to far-reaching demands from the Trump administration.