The Chinese government has announced buyers of two metals used in computer chips and solar panels will need to apply for export permits, starting on Aug. 1. The metals, gallium and germanium, are also used in military applications.

The U.S. has been imposing trade limits for several years to try to restrict China's access to semiconductor technology. In a statement, China's Commerce Ministry said the new controls on exporting the metals are to safeguard China's national interests.