As temperatures and tensions increase, the measures targeting Can$16.6 billion (US$12.6 billion) in USA steel, aluminum and consumer goods will take effect on Sunday, when Canadians celebrate a national holiday and just days before Americans celebrate Independence Day amid a heatwave expected in both countries.
The effort to restart stalled negotiations on the North America Free Trade Agreement comes with Canada and the USA swapping punitive tariffs on imports in an ongoing cross-border trade fight.
The new Canadian tariffs, which took effect at 12:01 a.m. Sunday, are hitting a long list of USA consumer goods, including ketchup and other Kraft Heinz products.
The tariffs on American products went into full effect Sunday, July 1.More news: Did Vladimir Putin phone call inspire Russian Federation to beat Spain?
"We will not escalate, and we will not back down", said Chrystia Freeland, Canada's foreign minister.
That comment seemed to refer less to the US elections and more to the vote on Sunday that's expected to sweep Andres Manuel Lopez Obrador into power as Mexico's first leftist leader in decades - certainly an "interesting" outcome for Trump and others.
Until Lopez Obrador is sworn in, members of the current Mexican administration will continue to serve as the country's lead NAFTA negotiators, the official said.More news: 1 dead, 9 injured as tour boat explodes in Bahamas
In an interview that aired Sunday on Fox News, Trump said he could quickly sign a revised NAFTA with Canada and Mexico, but instead wants to land a better deal for the U.S. Asked about the timing of an agreement, Trump said: "I want to wait until after the election".
Our neighbours down south visiting Canada's biggest tourist attraction say this trade war is hurting both countries.
Many U.S. manufacturers have decried the tariffs. Do you know what happened?
President Trump had enraged Canada and other US allies by declaring imported steel and aluminum a threat to America's national security and therefore a legitimate target for USA tariffs. "Everybody said, 'Uh, can we get on to another subject?"'More news: Neymar, Roberto Firmino Push Brazil Past Mexico at 2018 World Cup
"The two leaders agreed to stay in close touch on a way forward", it added.