The US Department of Defence has proposed a rule that would make it difficult for universities to engage foreign scientists in any work the department funds.
It is the latest in a series of initiatives intended to minimise the risk of certain technologies falling into the hands of countries that the United States views as security threats.
To comply with the proposed rule, universities and companies doing work funded by the department would need to obtain special licences to employ foreign scientists, and control their access to project information.
This could include making foreign nationals wear badges and work in segregated areas.
The proposed rule was published in the 12 July Federal Register and will be open for comment until 12 September.