OTTAWA, June 1 (Xinhua) -- Canada on Friday filed a challenge at the World Trade Organization (WTO) against the U.S. tariffs on steel and aluminum, hours after the European Union (EU) initiated a dispute with the United States at the WTO.

"These unilateral tariffs, imposed under a false pretext of safeguarding U.S. national security, are inconsistent with the United States' international trade obligations and WTO rules," Foreign Minister Chrystia Freeland said in a statement.

"Canada will closely collaborate with the European Union, which also filed a WTO challenge today, as well as with other like-minded countries, on opposing these tariffs," she said.

Despite worldwide objection, the U.S. administration decided in March to impose a 25-percent tariff on steel imports and a 10-percent tariff on aluminum imports.

On Thursday, U.S. President Donald Trump announced a decision not to extend the temporary steel and aluminum tariff exemptions against the EU, Canada, and Mexico, causing strong criticism.

The Canadian foreign minister said on Thursday that her country will impose retaliatory tariffs on up to 16.6 billion Canadian dollars (12.8 billion U.S. dollars) worth of U.S. steel, aluminum and other products.