China has announced it is banning exports to the United States of gallium, germanium, antimony and other key high-tech materials with potential military applications.
The move is seen as retaliation over the US limiting semiconductor-related exports.
The Chinese Commerce Ministry announced the move after Washington expanded its list of Chinese companies subject to export controls on computer chip-making equipment, software and high-bandwidth memory chips.
Such chips are needed for advanced applications.
The ratcheting up of trade restrictions comes as President-elect Donald Trump has been threatening to sharply raise tariffs on imports from China and other countries, potentially intensifying simmering tensions over trade and technology.