Washington and London on April 12 prohibited metal-trading exchanges from accepting new aluminum, copper, and nickel produced by Russia and barred the import of the metals to the United States and Britain. The action, aimed at disrupting Russian export revenue from the metals, comes as Washington seeks to punish Moscow for its invasion of Ukraine. Russia is a major producer of aluminum, copper, and nickel. The U.S. Treasury Department said action would prohibit the London Metal Exchange and Chicago Mercantile Exchange from accepting new Russian production of aluminum, copper, and nickel.