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.

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.