President Donald Trump signed an order Monday imposing global tariffs of 25% on all steel and aluminum imports in a move that will likely please domestic steelmakers but hurt allies like Canada and Mexico.

European leaders said they would respond firmly to higher levies on steel and aluminum, but they had yet to say what that retaliation would look like.

The European Union plans to retaliate against the United States for new steel and aluminum tariffs, adding another element to rising global trade tensions. "Unjustified tariffs on the EU will not go unanswered—they will trigger firm and proportionate countermeasures,