The Biden administration is placing restrictions on the export of Nvidia's artificial intelligence computer chips to certain Middle Eastern countries due to concerns about aiding potential adversaries. Nvidia disclosed the new export controls while announcing a $25 billion stock buyback. The specific countries affected have not been disclosed. Nvidia has previously complied with export controls in China by offering alternative products. The US government is also considering imposing export controls on advanced chips and AI technologies to China, but Nvidia does not believe this will significantly impact their financial results.