Donald's Trump's chief economic adviser said the U.S. pulled out of a G7 communique because the Canadian prime minister, Justin Trudeau, "stabbed us in the back" and accused the leader of one America's most important allies of playing a "sophomoric political stunt for domestic consumption". He said the Canadian leader must not have realized that Trump had televisions on Air Force One, allowing him to monitor Trudeau's news conference at the end of the G-7 summit.
The United States has alienated Canada and other allies by imposing tariffs on steel and aluminum imports, arguing that they pose a threat to US national security.
Larry Kudlow, a former CNBC commentator who is now Trump's top economic adviser, said Trudeau had engaged in "betrayal" of the U.S.
At a news conference Tuesday after his summit with North Korean leader Kim Jong Un, Trump recounted his recent tough exchanges with Trudeau.
Trump called Trudeau "very dishonest and weak", among other things.
Trudeau said in a press conference that Canada will "move forward with retaliatory measures on July 1, applying equivalent tariffs to the ones that Americans have unjustly applied to us".
"There's a special place in hell for any foreign leader that engages in bad faith diplomacy with President Donald J. Trump and then tries to stab him in the back on the way out the door", Navarro said in an interview with Fox News on Sunday.
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Asked if the administration will respect decisions from the World Trade Organization on tariffs, Kudlow said that "international multilateral organizations are not going to determine American policy".
"Canadians are polite and reasonable but we will also not be pushed around", he said.
A Trudeau spokesman, Cameron Ahmad, said on Saturday night that Mr Trudeau "said nothing he hasn't said before - both in public and in private conversations" with Mr Trump. The French presidency had earlier condemned "fits of anger".
Mulroney said he thought Trudeau's closing remarks were "fairly benign and certainly didn't warrant any attack". We have put up with Trade Abuse for many decades - and that is long enough.
But Trump had already said he would not hesitate to shut countries out of the USA market if they retaliate against his tariffs.
Meanwhile, the Canadian province of Quebec has offered $C100 million ($A101 million) in loans and guarantees for steel and aluminium companies hit by the U.S. tariffs. "The European Union is brutal to the United States". Trump said in a second tweet.
Threatening such a change could be another effort to advance the negotiations in order to secure a congressional vote on a revised deal by the end of the year, according to worldwide law firm Sandler, Travis & Rosenberg.