China imposed new export restrictions on two metals that are crucial to parts of the semiconductor, telecommunications and electric-vehicle industries, in an escalating technology trade standoff with the US.

Gallium and germanium, along with their chemical compounds, will be subject to export controls meant to protect Chinese national security starting August 1, China’s Ministry of Commerce said in a statement on Monday.

Exporters for the two metals will need to apply for licenses from the commerce ministry if they want to start or continue to ship them out of the country, and will be required to report details of the overseas buyers and their applications, it said.

Both gallium and germanium are key in the making of semiconductors and other electronics. Germanium is used in fiber optics and semiconductors, while gallium is used in making chipsets for electronic devices such as computer motherboards or portable phones.