US 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 US govt, according to people familiar with the matter and documents seen by the NYT.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. President Trump has sought for months to impose his political agenda on Harvard. The effort initially relied primarily on accusations that university officials had not done enough to address anti-semitism on campus. In recent weeks, however, the focus has expanded to other issues, including allegations about Harvard’s foreign ties, particularly to China. A spokesman for the treasury department declined to comment. A state department spokeswoman also declined to comment. A Harvard spokesman declined to comment.