The US government is preparing to curb the export of high-bandwidth memory (HBM) chips from the largest suppliers in the US and South Korea to Chinese companies, its latest move to limit China’s access to cutting-edge components, Bloomberg reported.

Restrictions, which could be put in place by next month, would cover advanced AI memory chips, including HBM2, HBM3 and HBM3E, the news agency noted.

The new curbs would hit SK Hynix, Samsung and US-based Micron Technology, which account for the vast majority of global HBM output.

To keep up soaring demand for memory chips driven by the AI boom, TrendForced reported in June Samsung and Micron are preparing to increase production capacity.

Chinese Foreign Ministry spokesperson Lin Jian stated in a daily briefing it “firmly opposes” the move, which undermines international trade rules, destabilises global industrial and supply chains.

He added: “China will keep a close eye on relevant developments. We hope relevant countries will firmly resist the coercion.”

The measure, if enacted, is expected to meet resistance from South Korea manufacturers.

Following pressure from the South Korean government late last year, the US granted Samsung and SK Hynix new waivers on export controls, allowing them to move ahead with plans to acquire chipmaking equipment to expand operations in China.

Bloomberg reported the latest measure would be part of broader package, including sanctions against more than 120 Chinese companies and new limits on US suppliers of chip equipment to the mainland.

In March, the US encouraged the Netherlands, Germany, South Korea and Japan to introduce chip restrictions on China as part of an effort to close export loopholes.