In a surprising reversal of the United States’ years-long technology restrictions on China, President Donald Trump last month allowed Nvidia to resume sales of a key AI chip designed specifically for the Chinese market.

The move could open the door to China securing more advanced computing power from the U.S. even as the two countries battled for technology supremacy, critics said.

For years, the US has restricted the sale of powerful AI chips to China. But Trump is letting sales of less-advanced chips happen.