The California-based company is a world-leading producer of AI semiconductors, and this month became the first company to hit $4 trillion in market value.

But it has become entangled in trade tensions between China and the United States, and Washington effectively restricts which chips Nvidia can export to China on national security grounds.

"Cybersecurity is critically important to us. Nvidia does not have 'backdoors' in our chips that would give anyone a remote way to access or control them," Nvidia said in a statement Thursday.

A key issue has been Chinese access to the "H20" -- a less powerful version of Nvidia's AI processing units that the company developed specifically for export to China.

Nvidia said this month it would resume H20 sales to China after Washington pledged to remove licensing curbs that had halted exports.

But the tech giant still faces obstacles -- US lawmakers have proposed plans to require Nvidia and other manufacturers of advanced AI chips to include built-in location tracking capabilities.

Beijing's top internet regulator said Thursday it had summoned Nvidia representatives to discuss recently discovered "serious security issues" involving the H20.

The Cyberspace Administration of China said it had asked Nvidia to "explain the security risks of vulnerabilities and backdoors in its H20 chips sold to China and submit relevant supporting materials".

China is aiming to reduce reliance on foreign tech by promoting Huawei's domestically developed 910C chip as an alternative to the H20, said Jost Wubbeke of the Sinolytics consultancy.

"From that perspective, the US decision to allow renewed exports of the H20 to China could be seen as counterproductive, as it might tempt Chinese hyperscalers to revert to the H20, potentially undermining momentum behind the 910C and other domestic alternatives," he said.

Other hurdles to Nvidia's operations in China are the sputtering economy, beset by a years-long property sector crisis, and heightened trade headwinds under US President Donald Trump.

CEO Jensen Huang said during a visit to Beijing this month that the company remained committed to serving local customers, adding that he had been assured during talks with top Chinese officials that the country was "open and stable".

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NVIDIA