Duke University is known as a relatively conservative place, compared with some other schools. It has still been a focus of Trump officials who say it has allowed diversity policies they say break the law.

“The consortia for H.I.V./AIDS vaccine development and immunology was reviewed by N.I.H. leadership, which does not support it moving forward,” said a senior official at the National Institutes of Health who was not authorized to speak on the matter and asked not to be identified.

At a college fair in Beijing organized by the American Embassy.