Homeland Security Secretary Kristi Noem on Thursday ordered the department to terminate Harvard University's Student and Exchange Visitor Program certification, the department said in a statement. Noem accused the university of "fostering violence, antisemitism, and coordinating with the Chinese Communist Party".
Harvard said the move by the Trump administration - which affects thousands of students - was illegal and amounted to retaliation.
The clampdown on foreign students marks a significant escalation of the Trump administration's campaign against the elite Ivy League university in Cambridge, Massachusetts, which has emerged as one of Trump's most prominent institutional targets. The move comes after Harvard refused to provide information that Noem had previously demanded about some foreign student visa holders who attend the university, the department said.
Harvard enrolled nearly 6800 international students in the 2024-2025 school year, amounting to 27 per cent of its total enrollment, according to university statistics.
"It is a privilege, not a right, for universities to enroll foreign students and benefit from their higher tuition payments to help pad their multibillion-dollar endowments," Noem said in a statement.
Harvard rejected the allegations and pledged to support foreign students.
"The government's action is unlawful," the university said in a statement.
"This retaliatory action threatens serious harm to the Harvard community and our country, and undermines Harvard's academic and research mission."
The university said it was "fully committed" to educating foreign students and was working on producing guidance for affected students.
Trump, a Republican, has undertaken an extraordinary effort to revamp private colleges and schools across the US that he says foster anti-American, Marxist and "radical left" ideologies. He has criticised Harvard in particular for hiring prominent Democrats to teaching or leadership positions.
Trump has frozen some $US3 billion ($A4.7 billion) in federal grants to Harvard in recent weeks, leading the university to sue to restore the funding.
