Donald Trump's administration on Thursday revoked Harvard's ability to enroll foreign nationals -- more than a quarter of the student body -- in a dramatic escalation of the US president's fight against the prestigious university.

The school in Cambridge, Massachusetts quickly slammed the move as "unlawful" and said it would hurt both the campus and the country, while one student said the community was "panicking."

Trump is furious at Harvard -- which has produced 162 Nobel prize winners -- for rejecting his demand that it submit to oversight on admissions and hiring over his claims that it is a hotbed of anti-Semitism and "woke" liberal ideology.

The loss of such a large proportion of the student body could prove to be a huge financial blow to Harvard, which charges tens of thousands of dollars a year in tuition.