Nvidia’s artificial-intelligence chips have been at the center of U.S.-China trade negotiations for months, yet it appears China is discouraging its companies from buying one of them: the H20s. Why? Sales of the chips to Chinese companies helped get China to agree to reboot its exports to the U.

Beijing has urged local companies to avoid using Nvidia Corp.’s H20 processors, particularly for government-related purposes, complicating the chipmaker’s return to China after the Trump administration reversed an effective US ban on such sales.

Trump said Monday that he has cut a deal with chipmaker Nvidia, allowing it to sell certain artificial intelligence chips to China in exchange for a cut of the revenue, which would go to the U.S. government. Trump said he also negotiated a similar deal with chipmaker Advanced Micro Devices (AMD).