Secretary of State Marco Rubio is pushing to investigate whether Harvard University violated federal sanctions by collaborating on a health insurance conference in China that may have included officials blacklisted by the U.S. government, according to people familiar with the matter and documents reviewed by The New York Times.

Mr. Rubio signed off on a recommendation to the Treasury Department last month to open an investigation, which experts and former Treasury officials said was an unusual attempt from a cabinet secretary to target a domestic entity for sanctions enforcement.

Whether the agency within the Treasury that handles sanctions, the Office of Foreign Assets Control, opened an investigation in response was unclear — but such a move could expose Harvard to significant legal risks. Mr. Rubio’s action is the latest example of the Trump administration’s whole-of-government approach to bringing the Ivy League university to heel.

President Trump has sought for months to impose his political agenda on Harvard by reshaping its curriculum, admissions and hiring processes. The effort initially relied primarily on accusations that university officials had not done enough to address antisemitism on campus. In recent weeks, however, the administration’s focus has expanded to other issues, including allegations about Harvard’s foreign ties, particularly to China.

A potential sanctions investigation demonstrates how Harvard’s problems with the government extend far beyond questions of whether the school will continue receiving federal funding. Mr. Trump and his allies appear determined to upend nearly all aspects of the institution, which has long symbolized the pinnacle of higher learning in the country and attracted influential scholars from around the globe.

A spokesman for the Treasury Department declined to comment on a possible or pending sanctions investigation. A State Department spokeswoman also declined to comment.