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.

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.

Mexico, Canada and the European Union on Tuesday condemned U.S. President Donald Trump's decision to impose tariffs on all steel and aluminum imports next month, a move that has fanned fears of a trade war as business and political leaders braced for yet more trade duty announcements from the new administration.

The president said he planned sweeping tariffs on all steel and aluminum imports on Monday and would take other action to even out tariff rates with the rest of the world later this week.

The European Union is preparing for a turbulent period in transatlantic relations as the Trump administration's trade policies and tech regulations challenge long-standing agreements and potentially destabilize Europe's economy and security.

The European Union plans to safeguard its economic interests by imposing countermeasures in response to the U.S. tariffs, according to EU officials.

The US president announced the introduction of a generalized 25% tariff on the two metals and their processed products. As often with Donald Trump, it's not easy to distinguish between bluff, intimidation,

The European Commission said on Friday it saw no justification for U.S. President Donald Trump's proposed "reciprocal" trade policy and would react "firmly and immediately" against tariff increases resulting from it.

The EU will always protect European businesses, workers and consumers from ‘unjustified tariff measure’, the European Union Commission said on Friday. It promised to take immediate action against the tariffs imposed on its exports.