Nvidia said on Thursday that the US government has allowed exports and in-country transfers needed to complete the development of its flagship artificial intelligence chip. The disclosure comes a day after Washington told the company to stop exporting its two top computing chips for AI work to China, a move Nvidia said could interfere with the development of the H100 chip it announced this year. The ban signalled a major escalation of the US crackdown on China's technological capabilities as tensions bubble over Taiwan, where chips for Nvidia and almost every other major chip firm are manufactured. The ban, which affects Nvidia's A100 and H100 chips designed to speed up machine learning tasks, sent the company's shares down 4 per cent before the bell. In its statement on Thursday, Nvidia said US officials have authorised it to perform exports needed to provide support for US customers of A100 through to March 1, 2023. Chinese customers are still required to obtain licenses from the US government for the technology, a spokesperson for Nvidia said. "On the surface, it looks like the US government is looking to refrain from sales of next generation advanced chips, 7 nanometers and below, specifically for military end use in China," said CFRA Research analyst Angelo Zino. Experts said the curbs are likely to hit almost any major tech company running public clouds or advanced artificial intelligence training modules in China. Rival Advanced Micro Devices, whose shares were down 3 per cent, was also asked on Wednesday to stop AI chip exports to China. The company did not respond to a request for comment on whether it received a similar authorisation.