U.S. blacklists seven Chinese companies over national security

The U.S. on Thursday announced it has added seven Chinese supercomputing companies to its "entity list" of export controls.

In a statement, the U.S. Department of Commerce said the companies conducted activities that are contrary to the national security or foreign policy interests of the U.S.

China has repeatedly voiced opposition to the U.S. cracking down on Chinese firms over a national security threat.