Two of America’s top chipmakers have been ordered by US regulators to halt exports of some of their artificial intelligence (AI) technology to China. In a regulatory filing, Nvidia said that it had been told by the US Department of Commerce that the requirement was due to a potential risk of the products being used by, or diverted to, a “military end-user”. The restrictions cover Nvidia’s A100 and forthcoming H100 integrated circuits, and any systems that include them. The enforcement of this measure would threaten $400m (345m) worth of business for the company, according to the filing. AMD has also...