Shares of major chipmakers Nvidia and AMD have fallen amid concerns of new U.S. restrictions on the sale of artificial intelligence chips to China.

Nvidia says the U.S. government requires a new license, effective immediately, to address the risk of chips being "used in, or diverted to a 'military end use'... in China and Russia."

There are fears the rule could lead to millions of dollars in lost revenue. Shares of both chipmakers slipped in after-hours trading in New York Sept. 1. Nvidia's shares were down by 6.6% while AMD slipped 3.7%.

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The new restrictions are a "gut punch for Nvidia", Dan Ives of Wedbush Securities told the BBC.
Chinese officials have firmly opposed the latest move. In a statement, Beijing said "The U.S. side should immediately stop its wrongdoing, treat companies from all over the world including Chinese companies fairly, and do more things that are conducive to the stability of the world economy."

The U.S. Commerce Department told the BBC, "We are taking a comprehensive approach to implement additional actions necessary related to technologies, end-uses, and end-users to protect U.S. national security and foreign policy interests."