A group of leading Senate Democrats, including Majority Leader Chuck Schumer and Senators Elizabeth Warren and Mark Warner, have sent a letter to U.S. Commerce Secretary Christopher Lutnick urging the department to maintain current restrictions on the sale of advanced artificial-intelligence chips to China. The lawmakers warn that resuming exports could pose significant national-security risks by enabling Beijing to accelerate military and surveillance capabilities. Their letter comes as chipmakers such as Nvidia and AMD lobby for permission to restart shipments that were halted under earlier U.S. export controls. The Senate Democrats’ intervention increases political pressure on the Commerce Department and the Biden administration, signalling strong congressional opposition to any loosening of semiconductor curbs aimed at China.