Prime Minister Justin Trudeau will host a Canada-U.S. economic summit in Toronto on Friday, days after President Donald Trump said he would hold off on deploying his threatened tariffs against Canada for a month.

Justin Trudeau announced some of the 25% tariffs against the U.S. would begin on Tuesday in response to Donald Trump's punishing tariffs on Canadian goods.

Tim McMillan, a former head of the Canadian Association of Petroleum Producers, warned that Ottawa should avoid the temptation to retaliate by cutting off oil supplies from Alberta, which make up half of U.S. oil imports, saying it “would be a huge mistake.”