Washington DC - President Donald Trump said Tuesday that he will cut funding for schools that allow "illegal protests" in his latest threat to civil liberties in the US.

The Republican has previously threatened to cut government funds to US colleges, schools, and universities if they teach about gender and race, allow transgender athletes to compete on girls' sports teams, or insist on Covid-19 vaccine mandates.

"All Federal Funding will STOP for any College, School, or University that allows illegal protests," he wrote on his Truth Social platform.

"Agitators will be imprisoned/or permanently sent back to the country from which they came. American students will be permanently expelled or, depending on the crime, arrested. NO MASKS!" he added.

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Trump has repeatedly threatened to turn the US education system upside down, including by defunding the entire Department of Education and returning all control over the curriculum to individual states.

His statement came after campuses were roiled last year by student protests against the US-facilitated Israeli destruction of Gaza.

On Monday, the Trump administration said it was considering scrapping more than $50 million in contracts with New York's Columbia University over allegations it failed to protect pro-Israeli Jewish students.

Those protesting in solidarity with Palestinians, meanwhile, have been subjected to brutal police interventions – requested by their own university administrators – while also being expelled in some cases for their advocacy.