Hours after the Department of Homeland Security pulled the plug on Harvard University’s enrollment of foreign students, the institution has sued the Donald Trump administration and filed a restraining order to temporarily block the decision. 

“We condemn this unlawful and unwarranted action,” President Alan Garber of Harvard University wrote to the school’s community on Friday.

Mr Garber said the revocation of Harvard’s certification under the Student and Exchange Visitor Programme “imperils the futures of thousands of students and scholars across Harvard and serves as a warning to countless others at colleges and universities throughout the country who have come to America to pursue their education and fulfil their dreams.”

In the lawsuit, Harvard accused the administration of a “campaign of retribution” given that the school had rebuffed Mr Trump’s demand to cancel Diversity, Equity, and Inclusion (DEI) programmes and to intensify scrutiny of international students’ political ideologies.

The Trump administration and Harvard have continued to lock horns after the president accused the Ivy League institution of not adopting adequate security measures to protect Jewish students from protests that erupted in the wake of the Israeli-Gaza war.

All of Mr Trump’s efforts to pressure Harvard to give in to his demands, including halting over $2 billion research funding and threatening to strip the university’s tax-exempt status, failed as the Ivy League institution refused to cave.

“Harvard can no longer enrol foreign students, and existing foreign students must transfer or lose their legal status,” said the U.S. Department of Homeland Security in a statement on Thursday.