In a rare show of unity, Opposition Members of Parliament are standing behind Prime Minister Justin Trudeau's promise to fight new tariffs from the United States.
"It would be with regret but it would be with absolute clarity and firmness that we move forward with retaliatory measures on July 1, applying equivalent tariffs to the ones that the Americans have unjustly applied to us", said Trudeau.
The spat has also drawn in Germany and France, who sharply criticised Mr Trump's decision to abruptly withdraw his support for a G7 communique hammered out at a Canadian summit, accusing him of destroying trust and acting inconsistently.
Dairy has emerged as the latest flashpoint between the US and Canada as they renegotiate the 1994 North American Free Trade Agreement.
Larry Kudlow, director of the National Economic Council, lashed out at Trudeau as "amateurish" and "sophomoric".
The DFC's Wiens said giving up further market share would "make it very hard for us to continue the growth and investment we've seen in the past several years".
The picture (and many memes) have since gone viral on the internet, and Trump raised it himself at the news conference after he was asked about his relationship with Canadian Prime Minister Justin Trudeau.
Soon after Trump left the G7 summit he tweeted that he had instructed the House of Representatives not to endorse the final communique of the G7 summit due to Trudeau's "false statements at his news conference", as the Canadian prime minister dismissed USA metal tariffs as "insulting" and announced retaliatory measures.
"It's kind of like ... if you were sitting with a friend and then out of the blue, you just punched them in the face", he said. They didn't want me to see it, but we found it.
The U.S. actually has a trade surplus with Canada.
US trade officials are going further.
In recent trade deals with the European Union and a group of Asia-Pacific nations, Canada conceded larger tariff-free dairy quotas.
The foreign affairs minister will have her work cut out for her as she attempts to see Canada spared from the U.S.'s heavy-handed steel, aluminum and auto tariffs and mend the increasingly frayed relationship between the two countries. The U.S. had a trade surplus with Canada of $8.4 billion past year, according to the Office of the United States Trade Representative.