By Leah Schnurr and Andrea Hopkins
OTTAWA, March 1 (Reuters) - Canada will retaliate againstany U.S. tariffs on steel and aluminum products, officials saidon Thursday, as Ottawa faced what could be one of the biggesteconomic threats since Donald Trump became President.
Trump unveiled the tariffs on Thursday but did not makeclear whether they would apply to Canada and Mexico, whichtogether with the United States are trying to renegotiate theNAFTA trade deal.
"Should restrictions be imposed on Canadian steel andaluminum products, Canada will take responsive measures todefend its trade interests and workers," Foreign MinisterChrystia Freeland said in a statement, calling any traderestrictions "absolutely unacceptable."
She did not give details and Canadian officials were notimmediately available for comment.
Canada buys more American steel than any other country,accounting for 50 percent of U.S. exports, and the steel andaluminum industry is highly integrated, Freeland added.
Miner Rio Tinto said it would continue to engagewith U.S. officials to underscore the benefits of the integratedNorth American aluminum supply chain. Canada is the world'slargest supplier of aluminum to the United States.
“Aluminum from Canada has long been a reliable and secureinput for U.S. manufacturers – including the defense sector,”Rio said in a statement.
The Trump administration - which Freeland generallydescribes as the most protectionist since the 1930s - has soughtto impose tariffs on Canadian softwood lumber and airliners overthe last year.
Canada pushed back on both occasions and won a victory inJanuary when a U.S. tribunal rejected Boeing Co calls forpunitive duties against Bombardier Corp passengerjets.
"We will always be there to defend workers and industry. Weshowed it on softwood lumber and showed it with the Boeingcase," Trade Minister Francois-Philippe Champagne told reportersin Ottawa.
CIBC economists Royce Mendes and Avery Shenfeld said thetariffs "could be more biting for the Canadian economy thanprevious moves by the administration" and noted the prospectsfor retaliation were limited.
"In many cases, Canada doesn't have a domestic source ofsupply that would benefit from hitting U.S. goods with atariff," they said in a note to clients. Canada sends 75 percentof its goods exports to the United States.
International trade lawyer Mark Warner said Canada could ifit wished apply tariffs on steel or aluminum or other targetedproducts.
"My hope is that the government does not respondprecipitously in tone or action and continues to work for anexemption," he said by e-mail.
(Additional reporting by Susan Taylor in Toronto, writing byDavid Ljunggren; editing by Grant McCool, James Dalgleish andSusan Thomas)
