The US continued to apply indirect pressure on South Korea to restrict the export of high-bandwidth memory (HBM) chips to China, a move which could adversely impact domestic suppliers Samsung and SK Hynix, The Korea Herald reported.

During the Korea-US Economic Security Conference in Washington DC on 10 September, US Under Secretary of Commerce for Industry and Security Alan Estevez urged chipmakers to only supply HBM to allies and for South Korea to back new US restrictions, the newspaper wrote.

Estevez suggested China should be barred from importing advanced GPUs which power AI applications because they can be used for military purposes.

South Korea Trade Minister Cheong In-kyo expressed concern about new restrictions, given two of three global producers are Korean. He added the US has not made an official announcement, with the countries expected to hold discussions on the matter, The Korea Herald stated.

SK Hynix and Samsung account for about 90 per cent of global HBM output. US-based Micron Technology is the only other manufacturer of HBM chips.

Samsung’s total sales to China rose 82 per cent year-on-year to KRW32.3 trillion ($24 billion) in H1, accounting for 16.1 per cent of total exports compared with 9.1 per cent, The Korea Herald rote.

SK Hynix’s shipments more than doubled to KRW8.6 trillion.

The companies did not break down exports of HBM chips.

Bloomberg reported in early August the US was considering controls on the export of advanced AI memory chips to China including HBM2, HBM3 and HBM3E.

The US Department of Commerce last week introduced a draft of export controls covering quantum computing, advanced chipmaking equipment, gate all-around field-effect transistors and 3D printing.