BEIJING, Nov. 18 (Xinhua) -- China's commerce ministry on Tuesday said that the United States' recent revision of its patent rules constitutes a discriminatory restriction on the legitimate rights of Chinese companies.

The comments were made in response to a media inquiry on a memorandum issued by the United States Patent and Trademark Office that revised transparency rules related to patent invalidation petitions, with a particular focus on applications submitted by entities with foreign backgrounds.

The move, which was made in the name of "national security," has violated the United States' international obligations on intellectual property protection and amounts to a discriminatory restriction on the legitimate rights of Chinese enterprises, according to a spokesperson for the Ministry of Commerce.

China will follow all developments closely, and will take necessary measures to firmly safeguard the legitimate rights and interests of Chinese companies, the ministry said.■