More than 300,000 federal student loan borrowers have exited the defunct SAVE repayment plan in recent weeks, but millions remain at risk as deadlines approach.

Nicholas Kent, a top official at the U.S. Department of Education, told CNBC on Thursday that borrowers still enrolled in the Biden-era Saving on a Valuable Education, or SAVE, plan could soon face significantly higher monthly payments if they fail to switch to a new repayment option.

Kent is a senior Trump administration official who helps oversee federal student aid policy and the government's student loan system.

"It's a problem for borrowers," Kent said. "They're not recognizing the benefit of making their payments."

He also delivered a blunt message: "SAVE borrowers have to move."