Trump’s steel fees could lead to a broader trade war as the EU threatens “proportional measures.”

The European Union plans to retaliate against the US over new steel and aluminum tariffs, adding another factor to the growing tensions in global trade.

“Unjust EU tariffs will not be unanswered. They will cause solid and proportionate measures,” European Commission’s Ursula von der Reyen said in a statement late Monday. The European Commission is the EU’s executive body.

The statement comes after President Donald Trump signed an executive order to impose a 25% tariff on steel and aluminum. American Steelmakers shares were repeated sharply on Monday following the order.

Taxes are effectively taxes paid to import goodness into a country. Latest tariffs could raise prices for foreign steel, which will help support steel producers at the expense of international competitors. Von Der Leyen called the tariffs “bad for business, bad for consumers.”

Trump has taken a proactive approach with tariffs early in his second tenure at the White House. He has already ordered tariffs in China, Canada and Mexico. Tariffs in Canada and Mexico were delayed by a month later.

Europe is not just opposed to US tariffs. Last week, China announced a new taxation on Select US Imports.

Reuters reports that von der Leyen is scheduled to meet Vice President J.D. Vance on Tuesday.

Rising trade tensions occur when inflation in both the US and the world has not yet returned to pre-pandemic levels. Some economists warn that tariffs can be passed on to consumers in the form of higher prices.