WASHINGTON >> The Trump administration has threatened to block Harvard University from enrolling international students unless the school hands over detailed records about the student body, in another escalation of the federal government’s fight against higher education.

In a letter sent Wednesday, Homeland Security Secretary Kristi Noem asked for “relevant information” on each student-visa holder at Harvard who had been involved in “known illegal” or “dangerous” activity.

She also requested information on the coursework of student-visa holders, to verify that they had taken enough classes to “maintain nonimmigrant student status.”

“It is a privilege to have foreign students attend Harvard University, not a guarantee,” Noem wrote in the letter, which was obtained by the New York Times. “The United States government understands that Harvard University relies heavily on foreign student funding from over 10,000 foreign students to build and maintain their substantial endowment.”The university, Noem added, “has created a hostile learning environment for Jewish students” because of its “failure to condemn antisemitism.”

How feud with administration escalated

The letter was sent after Harvard refused President Donald Trump’s demands to make sweeping changes to its admissions and hiring policies. The White House hit back with financial threats and penalties, including freezing $2.2 billion in multiyear grants to the university, along with a $60 million contract.

Trump has also threatened Harvard’s tax-exempt status, even though federal law prohibits the president from “directly or indirectly” telling the IRS to conduct specific tax investigations. The IRS is still weighing whether to revoke the exemption, according to three people familiar with the matter.

Trump has targeted universities as his administration moves to eradicate diversity efforts and what it says is rampant antisemitism on campuses. But the administration’s demands of Harvard are much broader than that, including performing audits of the student body’s ideological views.

Officials have suspended hundreds of millions of dollars in federal funds for research at universities across the country, taking particular interest in some of the most prominent schools, including Harvard.

The sweeping request from Noem comes as hundreds of international students across the United States have had their visas revoked in recent weeks, causing alarm on campuses and a string of federal lawsuits seeking to overturn the decisions. In other cases, officials from Immigration and Customs Enforcement have arrested students for protesting against Israel on college campuses.

Harvard’s response

Sarah Kennedy O’Reilly, a Harvard spokesperson, said the university was aware of the letter from Noem, which she said “follows on the heels of our statement that Harvard will not surrender its independence or relinquish its constitutional rights.”

“We continue to stand by that statement,” Kennedy O’Reilly said.

Noem wrote that ICE’s Student and Exchange Visitor Program could withdraw its approval of Harvard as a school that international students can attend if it did not meet a demand for records by April 30.

Her demand also included information about campus “disciplinary actions taken as a result of making threats to other students or populations or participating in protests which impacted their nonimmigrant student status.”

It was the Trump administration’s latest move against Harvard after the school refused this week to cave to what the school’s president called “assertions of power, unmoored from the law.”

“This newer tactic will damage the reputation of U.S. higher education long earned over the course of centuries, and compromises the U.S.’s position as the global leader in higher education,” said P. Deep Gulasekaram, a professor of immigration law at the University of Colorado Law School. He said it would “also more systemically and long term degrade the incentives for the best and brightest from around the globe to come to the U.S. to study, research and innovate.”

Financial impact

Harvard has a higher percentage of international students than the average American college. About one-fourth of its roughly 25,000 students, both graduate and undergraduate, are foreign.

Although Harvard is among the 20 American universities with the highest percentage of international undergraduate students, it is likely that the school relies less on income from those students than almost any other major college in the country.

Unlike some schools that work to attract wealthy international students to shore up their bottom lines, Harvard attracts undergraduate applications from international students who do not have the wherewithal to pay, according to Terry Mady-Grove, a college admissions adviser in Port Washington, N.Y.

“Harvard provides the same financial aid to domestic and international students,” Mady-Grove said in an email. “So, the financial impact on Harvard would be less than at other institutions.”

The financial aid package was recently increased to cover the full cost of attendance for students from families with annual incomes of $200,000 and below. The package — the same for domestic and international undergraduates — includes not only the annual tuition, but housing, food and health insurance for students whose families make less than $100,000 each year.

For these students, Harvard even throws in money for a winter coat.