Some of the highlights: Presidential proclamations, signed March 8, set in motion a new tariff regime created to come into effect 15 days after signing, .
Trump during a call, also stressed the need for early conclusion of negotiations on the NAFTA (North American free trade agreement).
Trudeau called his American counterpart during a tour of aluminum facilities in Quebec, on a day the prime minister did American television interviews to promote the integrated Canada-U.S. economy.
Marie and Regina, was held after United States President Donald Trump threatened Canada and Mexico with tariffs on steel and aluminum.
But both Mexico and Canada have rejected Trump's linkage of the levies to the ongoing Nafta talks. On Saturday, Cecilia Malmström, the European Union's trade commissioner, met with the United States trade representative, Robert Lighthizer, in Brussels, after a meeting that also included Japan to talk about steel overcapacity.More news: Annual Wichita Falls Egg Hunt Saturday
"One way of doing that is to put on a tariff, which makes imported goods more expensive and makes it more likely that the domestic firms will be able to continue production", he adds.
"We recognize that the American side is eager to get forward motion on NAFTA", Trudeau told CNN's Anderson Cooper, in one of his USA interviews. New tariffs dominate a busy news cycle.
Canada, the top supplier of steel and aluminium to the U.S. market, has been temporarily exempted from the tariffs, along with Mexico.
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. Later this week Trudeau is due to visit the steel town of Hamilton, where workers are on edge.
"We'll just respond the way we have, with focus on the work we do together and not too much worry about the rhetoric", he said.More news: Big Bang's Seungri reveals enlistment plan
Trudeau said Canada already has "significant barriers" in place to prevent low-priced steel and aluminum from being dumped there, and is prepared to work with Washington to "do even more". Those tariffs would be crippling to the Canadian steel industry, which provides direct employment to 10,000 in the Hamilton area alone.
But as much as the steel industry has shrunk over the years, the US still produces millions of tons of it each year, Lardy says. Chinese commerce minister Zhong Shan said, "There are no winners in a trade war".
Lardy says the tariffs could invite retaliation by other countries.
Trudeau said Canada still had a lot more work to do and would press Washington to ensure the exemptions were permanent, and Canada has emphasized that tariffs would hurt both the United States and Canada.
Azevedo said he did not know if Brazil would resort to the WTO's dispute resolution mechanism but said Brazil was not ruling it out.More news: 'The Cher Show' sews up costume designer Bob Mackie