Columbia University must take a series of “critical next steps” if it wants to restore $400 million in federal funding, the Trump administration said in a letter to the school.

A letter framed demands as "preconditions" for negotiations on Columbia's financial relationship with the federal government.

Federal agents searched two student residences at Columbia University, its interim president said, a week after immigration agents detained Mahmoud Khalil, a leader of last year's campus protests, who the Trump administration wants to deport.

Columbia University's interim President Katrina Armstrong said that she was “heartbroken" by Homeland Security agents searching two students' rooms on campus Thursday night.