President Donald Trump signed an order Monday imposing global tariffs of 25% on all steel and aluminum imports, likely pleasing domestic steelmakers but hurting allies like Canada and Mexico.

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

Donald Trump's trade advisers were finalizing plans on Wednesday for the reciprocal tariffs the U.S. president has vowed to impose on every country that charges duties on U.S. imports, ratcheting up fears of a widening global trade war and threatening to add to already-sticky U.