The U.S. Commerce Department said Friday it is tightening export controls to restrict China’s ability to access certain high-end chips that could be used by Beijing to produce advanced military systems. The move is part of efforts to protect the United States’ national security and foreign policy interests, the department said in a press release, underscoring the intensifying competition between the world’s two largest economies over technology. The new rules target advanced computer chips and items intended for end-use in supercomputers. The U.S. government is concerned that such advanced sys…