The US Commerce Department says it will add China's state-owned nuclear power company to its list of entities that are banned from purchasing goods from US firms.
The department said China General Nuclear Power Group and three affiliates will be blacklisted on Wednesday.
It explained the company has been acquiring US technology and diverting it to military purposes.
The US government has put China's telecom giant Huawei and Chinese manufacturers of supercomputers on the list, describing them as a threat to national security.
The US on Tuesday announced it would postpone additional tariffs on some Chinese imports.
But it has made clear it will be tough on Chinese companies that set their eyes on US technology, as China aims to transform itself into a high-tech powerhouse.