"When Nvidia technology ends up powering China's military, that's not innovation; it's a security failure," the Select Committee on China said in an X post.

"Nvidia's products were used by DeepSeek and ended up supporting an AI model used by the PLA," it said, referring to China's People's Liberation Army.

California-based Nvidia is the world's most valuable company because its artificial intelligence chips are in such huge demand.

But it has been caught in a geopolitical tussle between the United States and China as they compete in the fast-moving AI sector.

An Nvidia spokesperson hit back at the claim, saying China "has more than enough domestic chips for all of its military applications, with millions to spare," and "it makes no sense for the Chinese military to depend on American technology."

"The administration's critics are unintentionally promoting the interests of foreign competitors," they added.

The post from the 23-member bipartisan committee included a copy of a letter addressed to US Commerce Secretary Howard Lutnick, detailing the allegations.

"Documents provided to the committee reveal Nvidia provided extensive technical support that enabled DeepSeek -- now integrated into People's Liberation Army (PLA) systems and a demonstrated cyber security risk -- to achieve frontier AI capabilities," it said.

Last year, a low-cost generative AI model from China's DeepSeek, on par with US rivals, upended assumptions of American dominance in the fast-moving field.

The committee's letter, dated Wednesday, said Nvidia had treated DeepSeek "as a legitimate commercial partner deserving of standard technical support."

But DeepSeek routes Americans' data to the Chinese government "through infrastructure tied to a US-designated Chinese military company," it said.

The letter also mentioned a Jamestown Foundation report from October, which cited PLA procurement documents to conclude that the Chinese military was using homegrown AI systems including DeepSeek, and planned to integrate it across its operations.

The lawmakers called for "clarifying guidance" on President Donald Trump's move to allow a high-end Nvidia AI chip, the H200 model, to be sold in China, softening restrictions imposed by his predecessor Joe Biden's administration.

Measures should be taken "to prevent prohibited end users from gaining the type of access the PLA gained from DeepSeek," they said.