Commission President Ursula von der Leyen said unjustified tariffs would prompt "proportionate and decisive countermeasures", echoing her vow on Tuesday of a "firm and proportionate" response to Trump's decision to impose tariffs on all steel and aluminum imports.

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.

The European Union hopes to avert a damaging trade war with the U.S. over impending metals tariffs by prioritising negotiations rather than retaliatory countermeasures, EU officials signalled on Wednesday.