"Additionally, although Canada and Mexico are now exempt from the tariff order, we are concerned that other trading partners will retaliate by imposing tariffs on USA exports and/or USA companies would experience limited access to other exports markets", Mr. Hanvey wrote.
Trump has linked permanent exemption to the successful renegotiation of the North American Free Trade Agreement, making the industry nervous.
"We're going to ensure that Canadian steel is Canadian steel", he said at Dofasco, where he also promised unspecified measures to better protect workers' pensions where companies go under, downsize substantially, or are otherwise bought out.
Moreover, even if the over-reliance on steel imports were truly "weakening the internal economy" and "shrinking [US] ability to meet national security production requirements in a national emergency", as stated in the report, it's ironic that President Trump would then grant exemptions to Canada and Mexico - the largest and fourth largest exporters of steel to the USA respectively.
NAFTA talks started seven months ago and the U.S.is starting to get antsy about getting a deal.
It was their first conversation since Trump last week imposed tariffs on imported steel and aluminum, raising trade tensions.
Trudeau said he was working in the interest of his nation, but said it is "very possible to get a good win-win-win" through the NAFTA negotiations.
The encouraging news is that there is nearly total unanimity that the tariffs would be just as harmful to the American economy as they would on this side of the border.
Prime Minister Justin Trudeau speaks with workers during a visit to Stelco Hamilton Works in Hamilton Ont., Tuesday, March 13, 2018.
Trudeau told another USA network that he sees them as separate issues: "We don't link together the tariffs and the negotiations with NAFTA", he told CNBC in an interview from a Quebec aluminum plant Monday.
European Union officials may challenge Trump's tariffs at the World Trade Organization, but that could be a long, drawn-out process.
"There is a global overcapacity issue and we are very pleased to work with our allies and friends to continue to counter that problem", he said. Those tariffs would be crippling to the Canadian steel industry, which provides direct employment to 10,000 in the Hamilton area alone.
Brazil has said it will seek exemption from the newly imposed tariffs.
As the United States tries to light a fire under NAFTA negotiations, Canadian Foreign Affairs Minister Chrystia Freeland says Canada will not be bullied or pressured by the United States as part of those talks.
Earlier on Monday, Finance Minister Henrique Mereilles said Brazil's government had not made a decision yet on how to respond to the tariffs and needed to see what exactly the United States wanted in negotiations.