A federal judge on Thursday temporarily blocked a proclamation by President Donald Trump that banned incoming foreign students from entering the US to attend Harvard University.

The proclamation, issued Wednesday, marked the latest attempt by Trump's administration to cut off the nation's oldest and wealthiest college from a quarter of its student body, which accounts for much of Harvard's research and scholarship.

Hours earlier, Harvard had filed a legal challenge asking for the federal judge to block Trump's order, calling it illegal retaliation for Harvard's rejection of White House demands. In an amended lawsuit filed Thursday, Harvard said the president was attempting an end-run around a previous court order.