Was the item, information or software to be shared, shipped, transmitted or transferred developed under a sponsored agreement imposing publication restrictions(1) beyond a brief review (up to 90 days) for patent protection and/or inadvertent release of confidential/proprietary information?
Research carrying publication and dissemination restrictions preclude characterization of the effort as "fundamental research." As a result, you may be facing prohibitions limiting the participation of foreign persons.
"Fundamental research" is basic or applied research in science or engineering, the results of which are intended to be shared with the interested scientific community or otherwise placed in the public domain. Fundamental research, by definition, is free of access, participation, or dissemination restrictions.
Fundamental research is granted special status by US export regulations, such that participation by foreign persons in such research does not require export licenses to be obtained. If the research is other than "fundamental," then the conduct and results of that research may be subject to the full array of export control restrictions.