China's top chipmaker Semiconductor Manufacturing International Corp said on Friday that it is assessing the impacts of the US government's move to add it to a blacklist of Chinese companies that Washington alleged to have connections with the Chinese military.

The company's stocks dropped 4 percent in Shanghai on Friday morning on the heel of the news, while its shares in Hong Kong suspended trading.

The US Department of Defense on Thursday designated a total of four additional companies as owned or controlled by the Chinese military, including SMIC, China Construction Technology Co Ltd and China International Engineering Consulting Corp.

The move brings the total number of Chinese companies blacklisted to 35. Reuters reported that though the list did not initially trigger any penalties, a recent executive order issued by the US President will prevent US investors from buying securities of the blacklisted firms starting late next year.