Taiwan joined a yearslong US campaign to curtail China’s technological ascent when it blacklisted the country’s AI and chipmaking champions, an unprecedented step that may signal a resurgent effort to isolate its powerful neighbor’s semiconductor sector.

The South China Morning Post reported that on Jun. 15, the International Trade Administration of Taiwan added Huawei, SMIC and many of their subsidiaries to its Strategic High-tech Commodities Entity List, which prohibits local firms from shipping to them without licensed government approval.

Chinese companies Huawei and SMIC may have a difficult time accessing resources needed to build AI chips, due to Taiwanese export controls.