China ordered key domestic companies to stop buying memory chips from Micron Technology following a cybersecurity review, ratcheting a trade war with the US which has sought to restrict the nation’s access to high-end components and chipmaking machinery.

The Cyberspace Administration of China’s Network Security Review Office noted operators of critical information infrastructure should stop purchasing Micron Technology’s products.

It stated its review found Micron Technology’s products have “relatively serious potential network security issues, which pose a major security risk” to the country’s information infrastructure supply chain.

The authorities explained China’s review of Micron Technology’s products is intended to prevent network security issues from “endangering the security of the country’s key information infrastructure, which is a necessary measure to maintain national security”.

Richard Windsor, founder of research blog Radio Free Mobile, wrote the findings of a seven-week review were not made public: “This opacity adds weight to the US Commerce Department’s view that the ban has no basis in fact,” dubbing the move “a tit-for-tat retaliation”.

Windsor pointed out the ban won’t hurt China as it can source the same memory chips elsewhere including South Korea. “I think it is clear that China acted on Micron because this is one company that it can be pretty sure that banning its products will cause no collateral damage.”

In late 2022, China prepared a CNY1 trillion ($142.2 billion) support package to boost its chip industry in the face of the US restrictions on acquiring advanced semiconductors and chipmaking equipment.

The US previously added new export restrictions on Chinese companies, requiring chipmakers to obtain a licence from the Department of Commerce to export certain advanced chips made outside of the nation.

It had earlier imposed restrictions on Huawei, Semiconductor Manufacturing International Corp and other Chinese companies.