U.S. Trade Representative Robert Lighthizer listed the countries likely to be excluded from President Donald Trump's new steel and aluminum import tariffs as Canada, Mexico South Korea, the European Union, Argentina and Brazil, according to a CNBC reporter March 21. Notable exceptions include China, which Washington is targeting with trade measures, and Japan. (The Japanese trade minister recently said he expected Japan to be exempted from the tariffs.) A 25 percent tariff on steel and a 10 percent tariff on aluminum will take effect March 23. The decision to impose tariffs on steel and aluminum was made following a U.S. Commerce Department report Feb. 16, which revealed that steel and aluminum imports threaten U.S. national security .