Harvard University professors are suing to block the Trump administration's review of nearly $9 billion in federal contracts and grants awarded to the Ivy League school as part of a crackdown on what it says is antisemitism on college campuses.

Two groups representing Harvard professors sued the Trump administration on Friday, saying that its threat to cut billions in federal funding for the university violates free speech and other First Amendment rights.

Harvard's borrowing plan follows a similar move by Princeton University, which announced on April 1 that it may issue about US$320 million in taxable bonds later this month. Princeton also revealed that the US government had frozen several research grants.