美国白宫：特朗普今日将签署行政令，把钢铁和铝的关税加倍；50%的钢、铝进口关税明日生效。

Core Viewpoint - The White House announced that President Trump will sign an executive order to double tariffs on steel and aluminum imports, with a 50% tariff set to take effect tomorrow [1] Group 1: Tariff Changes - The executive order will increase tariffs on steel and aluminum imports to 50% [1] - The new tariffs are expected to impact global trade dynamics significantly [1]