US President Donald Trump said on Thursday (April 17) that Harvard University is abusing its tax-exempt status as he escalated his fight with the institution.

"I think Harvard is a disgrace," Trump told reporters.

Trump threatened on Tuesday to strip Harvard of its tax-exempt status. CNN reported on Wednesday the U.S. Internal Revenue Service was making plans to rescind the tax-exempt status of Harvard and that a final decision was expected soon.

Harvard said there was no legal basis to rescind its tax-exempt status, saying such an action will be unprecedented, will diminish its financial aid for students and will lead to abandonment of some critical medical research programs.

Harvard defies Trump demands for policy changes, risking funding

The U.S. Department of Homeland Security said Harvard University will lose its ability to enroll foreign students if it does not meet demands from the Trump administration to share information on some visa holders, marking the government's latest escalation against the educational institution.

Republicans launch probe into top US university Harvard

Republicans in the US Congress announced an investigation into Harvard University on Thursday, accusing it of flouting civil rights law in an escalation of President Donald Trump's attacks on elite institutions.

The lawmakers wrote to the world-renowned education and research establishment demanding documents on its hiring practices, diversity programs and last year's pro-Palestinian campus protests.

The letter -- signed by House Oversight Committee chair James Comer and House leadership chair Elise Stefanik -- came with Trump seeking unprecedented levels of control over the country's oldest and wealthiest university.

Comer and Stefanik castigated Harvard President Alan Garber for rejecting demands for supervision by the White House, which has canceled $2.2 billion in funding and threatened further reprisals.

"Harvard is apparently so unable or unwilling to prevent unlawful discrimination that the institution, at your direction, is refusing to enter into a reasonable settlement agreement proposed by federal officials intended to put Harvard back in compliance with the law," they told Garber.

"No matter how entitled your behavior, no institution is entitled to violate the law."

Trump -- furious at Harvard for rejecting oversight of its admissions, hiring practices and political slant -- told reporters the university's conduct had been "horrific."

The president, who is in charge of every aspect of the federal government, said he was "not involved" in its fight with Harvard but had "read about it."

"I think what they did was a disgrace," Trump told reporters at the White House. "They're obviously anti-Semitic and all of a sudden, they're starting to behave."

Harvard is just the latest in a series of top universities and other institutions in the administration's crosshairs.

But while New York's Columbia University bowed to less far-ranging demands, Harvard flatly rejected the pressure, saying it would not "negotiate over its independence or its constitutional rights."

Trump said Harvard should lose its government research contracts and tax-exempt status, while administration officials threatened to ban the school from admitting foreigners, who make up more than a quarter of the student body.

Trump has also targeted Brown, Cornell, Northwestern, Pennsylvania and Princeton universities, threatening each with freezes of between $175 million and $1 billion, according to US media.

Republicans have said their campaign against universities is a response to what they call rampant anti-Semitism, following divisive protests against Israel's war in Gaza that swept campuses last year.

Columbia -- an epicenter of the activism -- agreed last month to oversight of its Middle Eastern studies department after being threatened with a loss of $400 million in federal funds.

Harvard staff and students rallied against the Trump administration in a campus protest Thursday aimed at encouraging university leadership to hold the line, research fellow Avi Steinberg told AFP.

"They actually want Harvard to make good on its promises to its students and its faculty to protect every single student on campus, to protect the faculty and especially faculty free speech," he said. With Agence France-Presse