President Trump barred most international students from entering the United States to study at Harvard University late Wednesday — escalating the Trump administration’s battle with the Ivy League school.

In a proclamation, Mr. Trump suspended the entry of foreign students or exchange visitors planning to go to Harvard, unless his administration determines somebody’s entry “would be in the national interest.” The order also directs Secretary of State Marco Rubio to consider whether student visa holders who are already in the U.S. “should have their visas revoked.”

The order claimed Harvard “is no longer a trustworthy steward of international student and exchange visitor programs,” accusing the school of failing to report students’ disciplinary records to the federal government and criticizing it for ties to researchers based in China.

CBS News has reached out to Harvard for comment.

The Trump administration has tried repeatedly to restrict Harvard’s ability to enroll international students — a serious threat for a school where more than one in four students hail from foreign countries. 

Last month, the Department of Homeland Security tried to take away Harvard’s certification in the federal government’s student visa database. A judge halted that policy after Harvard sued, with the school arguing the order was unconstitutional and would have an “immediate and devastating effect for Harvard and more than 7,000 visa holders.”

And last week, the State Department ordered embassies and consulates to conduct “additional vetting” of anybody who wants to travel to Harvard — including current and prospective students, faculty, guest speakers and even tourists — according to an email obtained by CBS News. 

This is a developing story; it will be updated.