The two economic superpowers have traded barbs this year over export curbs, with Washington notably raising the threshold for selling high-end semiconductors to China.

US President Donald Trump's administration has also accused Beijing of hindering exports of rare earths in retaliation against sweeping tariffs it imposed on Chinese goods.

Beijing's commerce ministry announced on Tuesday several adjustments to a list of technologies subject to export curbs.

It marked as "restricted" a technology for preparing battery cathode materials, meaning it cannot be exported without special permission.

The ministry also added five more "control points" to an already-restricted non-ferrous metallurgy technology involved in lithium mining and refining.

"This adjustment... is aimed at safeguarding national economic security and development interests, and promoting international economic and technological cooperation," the ministry said.

China leads the world in the production of lithium-ion batteries used to power electric vehicles -- another sector in which it is a major player.

Its alleged soft-pedalling on exports of rare earths -- crucial materials for making electronics and other goods -- came as the United States ramped up restrictions on the export of cutting-edge artificial intelligence (AI) chips to China.

Beijing received a modest boost on that front on Tuesday when US tech giant Nvidia said it expected to be granted a licence to sell one of its less-powerful AI chips to the Asian nation.