Suppliers of parts for Nvidia’s H200 have paused production after Chinese customs officials blocked shipments of the newly approved artificial intelligence processors from entering China, according to a report.

Nvidia had expected more than one million orders from Chinese clients, the report said, adding that its suppliers had been operating around the clock to prepare for shipping as early as March.

Chinese customs authorities this week told customs agents that Nvidia’s H200 chips were not permitted to enter the country, Reuters reported.

Sources have also said government officials summoned domestic tech firms to warn them against buying the chips unless it was necessary.