Chinese authorities summoned Nvidia Corp. to discuss alleged security risks related to its H20 chips, casting doubt over the domestic business of the world’s most valuable company.

China says Nvidia’s H20 chips may have serious security problems and has asked the company to explain. The US recently allowed Nvidia to sell the chips to China again, which upset some American lawmakers. Some US leaders worry the chips could help China build stronger AI and want answers about why the ban was lifted.

After Washington’s U-turn, Nvidia chief executive Jensen Huang visited Beijing to meet officials and customers. He stressed his company’s commitment to the Chinese market and introduced a new graphics processing unit based on the latest Blackwell series that is tailored to align with existing US export controls.