President Joe Biden has blocked the $14.1 billion sale of United States Steel Corp. to Nippon Steel Corp., killing a high-profile deal that sparked a political firestorm and tensions between the US and Japan.

Biden announced his formal decision on Friday after the case was referred to him by a US security review panel, ahead of a deadline early next week.

“U.S. Steel will remain a proud American company – one that’s American-owned, American-operated, by American union steelworkers – the best in the world,” the president said in a statement.