TORONTO -- U.S. President Donald Trump's 10-per-cent tariff on Canadian aluminum imports takes effect today, despite Canada's plan to hit back with $3.6 billion in countermeasures.

The U.S. administration announced the new tariff on Aug. 6 as aluminum organizations on both sides of the border condemned the move.

In announcing the new trade action, Trump claimed that the American aluminum business has been "decimated" by Canada, calling it "very unfair" and accusing Canadian producers of flooding the U.S. with exports.

Canadian and American aluminum groups have disputed that assertion, and other business groups have stated the tariffs will hurt businesses in both countries.

Within hours of Trump’s announcement, Deputy Prime Minister Chrystia Freeland said Canada plans to impose $3.6 billion in countermeasures on a "broad and extensive list" of aluminum products. She announced Aug. 7 that the federal government will consult industry with on a long list of American products that they are looking to level, in what will be a dollar-for-dollar response, although no further action has been announced.

Canadian officials had indications that this move was coming, and preparations have been underway for at least a month. Freeland said the "perfectly reciprocal" tariffs will take the exact same approach as the federal government took in 2018 when Trump hit Canada with steel and aluminum tariffs during negotiations for the new NAFTA deal.

Freeland called Trump’s tariffs "unnecessary, unwarranted and entirely unacceptable," and said they are the "last thing anyone needs" right now given the current state of the economy amid COVID-19.

The tariffs on unprocessed aluminum imports from Canada are being levelled under Section 232 of the U.S. Trade Expansion Act, which states the imports pose a threat to American national security.

With files from's Rachel Aiello