Wall Street index futures dropped on Wednesday and chip darling Nvidia slumped after the company flagged steep charges from new U.S. curbs on chip exports to China, fuelling worries about the fallout of an escalating trade war.

Suppliers to Nvidia Corp. saw share price declines in Asia after the chipmaker said the US government will begin requiring a license to export its H20 chips to China, an escalation of restrictions.

Chip stocks fell after new licensing requirements were imposed for the export of some artificial-intelligence semiconductors to China. The U.S. government will require licenses for the export of Nvidia‘s H20 and Advanced Micro Devices‘ MI308 AI chips as well as their equivalents,