The US is drawing a line in the sand for chip companies doing business with China, singling Nvidia out in particular.

The US has been passing export restrictions to prevent China from accessing the most advanced semiconductors, and especially those that can be used to power generative AI models. In response, Nvidia has designed chips specifically for the Chinese market, chips that fly under US sanctions but still give China some of the performance it’s seeking.

According to Fortune, US Commerce Secretary Gina Raimondo has laid down the gauntlet, warning Nvidia not to continue the practice:

“I know there are CEOs of chip companies in this audience who were a little cranky with me when I did that because you’re losing revenue,” she said. “Such is life. Protecting our national security matters more than short-term revenue.”

Speaking specifically to Nvidia, she continued:

“If you redesign a chip around a particular cut line that enables them to do AI, I’m going to control it the very next day,” Raimondo said.

The statements mark a significant escalation of the US’ efforts to isolate China’s tech industry.