The Chinese government has said it will ban exports to the US of some key components in making semiconductors, escalating trade tensions a day after Washington announced curbs targeting China’s ability to make advanced chips.

Among the materials banned from export were the metals gallium, antimony and germanium, China’s commerce ministry said in a statement that cited “national security” concerns.

Exports of graphite, another component in semiconductors, would be subject to “stricter reviews of end-users and end-uses”, the ministry said. The curbs strengthen enforcement of existing limits on critical minerals exports that Beijing began rolling out last year, but apply only to the US market.

“To safeguard national security interests and fulfil international obligations such as non-proliferation, China has decided to strengthen export controls on relevant dual-use items to the United States,” the ministry said.

Gallium and germanium are used in semiconductors, while germanium is also used in infrared technology, fibre optic cables and solar cells. Antimony is used in bullets and other weaponry, while graphite is the largest component by volume of electric vehicle batteries.

There is concern that Beijing could next target other critical minerals, including those with even broader usage such as nickel and cobalt.

China accounts for 94% of the world’s production of gallium, and 83% of germanium.

Chinese customs data shows there were no shipments of wrought and unwrought germanium or gallium to the US this year through October, when a year earlier it was the fourth and fifth-largest market for the minerals.

Similarly, China’s overall October shipments of antimony products plunged by 97% from September after Beijing’s move to limit its exports took effect.

On Monday, Washington announced restrictions on sales to 140 companies including Chinese chip firms Piotech and SiCarrier, expanding efforts to curb exports of state-of-the-art chips to China that could be used in advanced weapons systems and artificial intelligence.

The new US rules include controls on two dozen types of chip-making equipment and three kinds of software tools for developing or producing semiconductors.

On Tuesday, China said the US had “politicised and weaponised economic, trade and technological issues” as it unveiled its own export curbs.

The Chinese move also restricts the export of “dual-use items to United States military users or for military purposes”, Beijing said.

“The move is clearly a retaliatory strike at the US,” said Dylan Loh, an assistant professor at Singapore’s Nanyang Technological University.

“It drives home an important point which is that China is not completely passive [and] there are some cards it can play and hit the US with as well with regards to chips.”

These “back and forth curbs” could create supply chain disruption, as well as inflationary pressures, should they affect trade for third parties, said Chong Ja Ian, an associate professor of political science from the National University of Singapore.

Brady Wang, associate director at technology market research firm Counterpoint, told AFP that while the metals played critical roles in hi-tech industries, they were upstream in the supply chain, meaning the immediate impact on production was limited. “As the US-China trade tensions have persisted for some time, many intermediary manufacturers in the supply chain have been stockpiling these materials.”

Chinese trade associations released similarly worded statements on Tuesday urging their members to seek local alternatives to US chips.

The Internet Society of China called on companies to “be cautious when procuring US chips, seek to expand cooperation with chip companies in other countries and regions, and actively use chips produced and manufactured in China by domestic and foreign enterprises”.

The China Association of Automobile Manufacturers accused Washington of having “arbitrarily amended the control rules, seriously affecting the stable supply of US chip products”.

“The Chinese auto industry’s trust and confidence in the procurement of US chip products is being shaken, and US auto chip products are no longer reliable and safe,” the association said.

With Agence France-Presse and Reuters