The trade threats could reduce exports to the United States and dampen investment in Europe, dealing a blow to growth at a time when the continent is already facing a lackluster economy.

The European Commission said on Friday it would react "firmly and immediately" against tariff increases resulting from U.S. President Donald Trump's proposed reciprocal trade policy, which it labelled unjustified and a step in the wrong direction.

The European Union’s executive branch has vowed to “take firm and immediate action” against U.S. President Donald Trump’s imposition of tariffs on steel and aluminum.