The Trump administration announced Thursday it will impose tariffs on steel and aluminum imports from Europe, Mexico and Canada after failing to win concessions from the American allies. Europe and Mexico pledged to retaliate quickly, exacerbating trans-Atlantic and North American trade tensions. Commerce Secretary Wilbur Ross said the tariffs would be 25 percent on steel and 10 percent on aluminum, and go into effect on Friday, as the administration followed through on the penalties after earlier granting exemptions to buy time for negotiations. President Donald Trump had announced the tariffs in March, citing national security concerns. The European Commission’s president,...