NVIDIA Corporation (NASDAQ:NVDA) and Advanced Micro Devices, Inc. (NASDAQ:AMD) said the US government has told them to stop exporting certain high-performance chips to China.
In a regulatory filing, Nvidia said the block on its artificial intelligence (AI) enabling had been imposed due to risk of the products being used or diverted to a "military end user".
Tensions remain high in the US-China business and technology spheres, despite a rare agreement last week to audit US-listed Chinese companies.
Nvidia said the export ban refers to its A100 and H100 integrated circuits, and any systems that use them, with the move threatening to upend US$400mln of Nvidia's business.
In a filing last week, the California-based tech giant estimated that new requirements could affect its China sales.
Nvidia shares fell 6.36% in after-hours trading AMD by 3.7%.
Nvidia told CNN it was working with "customers in China to satisfy their planned or future purchases with alternative products" and may seek licenses in areas where replacement products are not sufficient.
The US Department of Commerce also mandated new requirements for AMD's MI250 integrated circuits shipments to China, reports CNN.
"At this time, we do not believe that shipments of MI100 integrated circuits are impacted by the new requirements," AMD said, referring to another line of components. "We do not currently believe it is a material impact on our business."
Nvidia and AMD noted the new mandate for chipmakers also bans exports to Russia, with both companies adding they do not currently sell any products to the country.