The three close USA allies had been part of a small group of foreign governments that received temporary exemptions from the tariffs, until trade deals could be signed.
"This is a bad day for world trade", European Commission president Jean-Claude Junker declared.
Brussels previously threatened to slap tariffs on USA products including bourbon, motorcycles and blue jeans. "I have argued for the European Union and the United States to engage in a positive trans-Atlantic trade agenda, and for the European Union to be fully, permanently and unconditionally exempted from these tariffs".
Mexico, the European Union and Canada immediately announced plans to retaliate with their own tariffs against American products.
Canada announced plans to slap tariffs on $12.8 billion worth of USA products, ranging from steel to yogurt and toilet paper.More news: Brad Stevens Prepares for Game 7 of the Eastern Conference Finals
Three other countries that were exempted from the initial tariff implementation - Argentina, Australia and Brazil - will be subject to arranged limitations on the volumes of steel and aluminum they can ship, instead of facing the import levies.
"He seemed to understand very clearly that national-security issues don't really apply when you talk about steel or aluminum from Canada", Trudeau said. The move marks the administration's most aggressive trade action yet against major US trading partners, which had been fighting for permanent relief.
The problems of steel dumping will not be solved by unfair tariffs, and steelworkers in the United Kingdom and US must not fall into the trap of believing rhetoric from the likes of Donald Trump.
Ross said Canada's and Mexico's exemptions were hooked to the progress of the NAFTA negotiations, which "are taking longer than we had hoped".
This comes after USA and EU trade officials spent two months trying to reach an agreement to create a tariff exemption for European countries.
European and United States equities lost ground slightly on fears the U.S. measures could spark a trade war.
"There are periodic disagreements between any two countries on any given set of topics".More news: Nadal, Sharapova survive scares as Serena returns
And it is not at all clear how taxing imports of Canadian and European steel and aluminum is going to get China to cut subsidies for its producers.
For instance, the Beer Institute - an industry group that represents U.S. brewers - warned that aluminum tariffs would drive up the price of beer cans.
Prices started rising even before all the tariffs kicked in.
Canadian and Mexican officials also threatened retaliatory responses but have as yet not indicated which US products they will target. The higher cost meant it lost out this year to a Chinese company on a contract to branch out into a new market: making food-processing equipment.
He said Canada would pursue retaliatory penalties on a range of United States goods.
In a statement released by Ontario NDP leader and Hamilton Centre MPP, Andrea Horwath said the announcement will immediately impose devastating tariffs on Canadian steel and aluminum - putting many thousands of good jobs in Ontario at risk.
Measured purely in dollars, the tariffs don't amount to much in America's $20 trillion economy.More news: Syria's Assad threatens to attack area under US-backed Kurds