News of a backlog at the U.S. federal department comes less than a week after national security experts urged the Trump administration to reverse its decision that allows Nvidia to export H20 chips to China.

NVIDIA has been called in by Chinese regulators over claims that its H20 AI chip poses security risks, putting billions in potential sales at stake.

China state media is calling for Nvidia Corp. to prove that its H20 chip is secure, saying it can’t allow flawed chips into the country.China’s top internet watchdog summoned Nvidia representatives earlier this week to discuss what Chinese officials called significant security vulnerabilities in the H20.