China on Friday strongly opposed the United States to unprovoked oppression of its companies and asked America to stop abusing the concept of national security after the Trump administration added SMIC and CNOOC to a defense blacklist.

"What the United States has done seriously violates the market competition principles and international economic and trade rules," foreign ministry spokeswoman Hua Chunying told a regular briefing, adding that "It will severely harm the U.S. interest and image."

The United States on Thursday added China's top chipmaker, Semiconductor Manufacturing International Corporation (SMIC), and oil giant China National Offshore Oil Corp (CNOOC) to a blacklist of so-called alleged Chinese military companies.

The U.S. Department of Defense designated a total of four additional companies as purportedly linked to the Chinese military, also including China Construction Technology Co Ltd and China International Engineering Consulting Corp.

The move brings the total number of companies blacklisted to 35. While the list did not initially trigger any penalties, a recent executive order issued by U.S. President Donald Trump will prevent U.S. investors from buying securities of the blacklisted firms starting late next year.

Read more: Trump's new executive order is largely symbolic, and a distraction

In a stock market statement, SMIC said it strongly opposed the decision, which reflected a fundamental misunderstanding by the U.S. administration of the end-uses of its business and technology.

"The Company's services and product are all for civilian and commercial end-uses and are not involved in any military application," SMIC clarified in its statement.

The company also said there was no major impact from its addition to the list. Its Hong Kong shares closed Friday down 5.4 percent after having resumed trading in the afternoon following a suspension.

CNOOC Ltd, the listed arm of CNOOC, said in an exchange filing that it is assessing the impact of the situation on the group and will closely monitor relevant follow-up developments.

(With input from Reuters)

(Cover image: Logos of SMIC and CNOOC. Gao Hongmei/CGTN)