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.

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 weeks after co-founder Jensen Huang met senior officials in Beijing.

The move came two weeks after the Trump administration reversed course to allow Nvidia to sell the coveted artificial intelligence chips in China.