After departing from the Quebec summit for Singapore, Trump tweeted that Trudeau's remarks at a news conference, where he said Canada would not be pushed around, "were very dishonest and weak".
"Our Tariffs are in response to his of 270% on dairy!" the US president tweeted.
And he said he had told Trump "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".
Canadian Prime Minister Justin Trudeau called USA metal tariffs "insulting" and announced retaliatory measures.
Trump said Saturday evening that he had instructed US officials to withdraw support for a joint statement with other member nations he had backed just hours earlier, saying the United States would not join after Trudeau publicly criticized Trump's trade policy.
"We strive to reduce tariff barriers, non-tariff barriers and subsidies", the statement said. Mr. Trump said the move would protect domestic producers that were vital to USA security.
"I think the G8 would be better, I think having Russian Federation back in would be a positive thing".
But during his comments Saturday morning, Trump raised multiple options for NAFTA, including a potential new deal or the possibility of doing separate deals with Mexico and Canada, effectively cleaving the longtime agreement in two.
"The United States will not allow other countries to impose massive Tariffs and Trade Barriers on its farmers, workers and companies". And I don't blame other leaders for that. The G-7 also includes Britain, Italy, France, Germany and Japan.
"It's a little worse within North America - the underlying bargain was that USA neighbors would receive special treatment", Alden said in the same press call.
On rating G7 friendships: "I would say that the level of relationship is a 10. Both of those things could happen", Trump said, warning that it would be "very bad" for Canada and Mexico if no deal could be reached among the three countries. "When I'm telling them, they're smiling at me". But this was more an indication of how poorly Mr Trump understands the global trading system than a serious summons to the negotiating table.
Trump fired off a pair of tweets several hours after leaving the summit in Canada to fly to Singapore for another on North Korea.
Russian Federation was thrown out of the group in 2014 over the annexation of Crimea. Kudlow said Trump won't let people "take pot shots at him" and that Trudeau "should've known better".
"President Trump and I had a brief word here at the summit about how he is looking forward to his visit to the United Kingdom and I look forward to welcoming him to the United Kingdom".
The US president has made it clear he believes the removal of tariffs against his G7 allies should come at a price - and he doesn't expect the US to pick up the tab.