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 European Union plans to retaliate against the United States for new steel and aluminum tariffs, adding another element to rising global trade tensions. "Unjustified tariffs on the EU will not go unanswered — they will trigger firm and proportionate countermeasures,