Hamilton, Canada - President Donald Trump's aggressive tariff policy has taken its toll on Canada's steel industry, a major company on Monday announcing mass layoffs to ensure its "survival."

Stelco Holdings Inc. on Monday announced it will idle part of its Hamilton plant, likely laying off around 500 employees, as it seeks to ensure its "survival" in the face of brutal US tariffs on Canadian steel exports.

An internal memo obtained by CBS News on Monday saw the company announce it will begin winding down its cold-rolled and coated operations on October 9. The measures should not impact its hot-rolled steel products.

"Obviously, we got to meet with the company, and find out who's getting laid off," said United Steelworkers Local 1005 President Ron Wells in a statement to CBC.

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"Christmas ain't that far away, and we have no idea the duration of these layoffs," he said. "People are concerned. I don't blame them."

Without making explicit reference to Trump's tariff policy, Stelco Vice President of Sales Frederic Fafard made it clear in the memo that the ongoing trade war was to blame for the mass layoffs.

Specifically, Trump's 50% tariff on Canadian steel and aluminum exports has taken a major toll on the industry.

This has been made worse by recent investments by Washington into homegrown steelmakers, such as a new $15 billion project in Minnesota that was announced on Monday.

The news comes a month after Ottawa walked away from an "uneconomic, unfair" trade deal with Washington. In response, Trump introduced 50% tariffs against $20 billion worth of Canadian goods, and Canadian Prime Minister Mark Carney responded in kind.

"This is an unfortunate but necessary action to help ensure the survival of Stelco in what has become a challenging and unsustainable market," Fafard said in the memo.