CAMBRIDGE, United States (AFP) — Harvard began its annual graduation ceremony Thursday as a federal judge considers the legality of punitive measures taken against the university by United States President Donald Trump that threaten to overshadow festivities.

Hundreds of robed students and academics squeezed onto the steps of the campus’s main library early Thursday as Trump piles unprecedented pressure onto the university, one of the most prestigious in the world.

He is seeking to ban it from having foreign students, shredding its federal contracts, slashing its multibillion-dollar grants and challenging its tax-free status.

Harvard is fighting all of the measures in court.

The Ivy League institution has continually drawn Trump’s ire while publicly rejecting his administration’s repeated demands to give up control of recruitment, curricula and research choices.

The government claims Harvard tolerates anti-Semitism and liberal bias.

“Harvard is treating our country with great disrespect, and all they’re doing is getting in deeper and deeper,” Trump said Wednesday.

Harvard president Alan Garber, who told National Public Radio on Tuesday that “sometimes they don’t like what we represent,” may address the ceremony, which will be attended by as many as 30,000 people.

Garber has acknowledged that Harvard does have issues with anti-Semitism, and has struggled to ensure that a variety of views can be safely heard on campus.

“The Covenant of Water” author Abraham Verghese will be the commencement speaker and will receive an honorary degree in front of crowds wearing academic garb.

Ahead of the ceremony, members of the Harvard band sporting distinctive crimson blazers and brandishing their instruments filed through the narrow streets of Cambridge, Massachusetts — home to the elite school, America’s oldest university.

A huge stage had been erected and hundreds of chairs laid out in a grassy precinct that was closed off to the public as the event got under way.

Students wearing black academic gowns also toured through Cambridge with photo-taking family members, AFP correspondents saw.

Madeleine Riskin-Kutz, a Franco-American classics and linguistics student at Harvard, said some students were planning individual acts of protest against the Trump policies.

“The atmosphere (is) that just continuing on joyfully with the processions and the fanfare is in itself an act of resistance,” the 22-year-old said.

– Legal fightback –

Garber has led the fightback in US academia after Trump targeted several prestigious universities — including Columbia, which made sweeping concessions to the administration in an effort to restore $400 million of withdrawn federal grants.

A federal judge in Boston will on Thursday hear arguments over Trump’s effort to exclude Harvard from the main system for sponsoring and hosting foreign students.

Judge Allison Burroughs quickly paused the policy which would have ended Harvard’s ability to bring students from abroad who currently make up 27 per cent of its student body.

Harvard has since been flooded with inquiries from foreign students seeking to transfer to other institutions, Maureen Martin, director of immigration services, said Wednesday.

“Many international students and scholars are reporting significant emotional distress that is affecting their mental health and making it difficult to focus on their studies,” Martin wrote in a court filing.

Retired immigration judge Patricia Sheppard protested outside Harvard Yard on Wednesday, sporting a black judicial robe and brandishing a sign reading “for the rule of law.”

Basketball star and human rights campaigner Kareem Abdul-Jabbar addressed the class of 2025 for Class Day on Wednesday.

“When a tyrannical administration tried to bully and threaten Harvard to give up their academic freedom and destroy free speech, Dr Alan Garber rejected the illegal and immoral pressures,” he said, comparing Garber to civil rights icon Rosa Parks.