In the two tweets that ended USA support for the joint G-7 statement, Trump accused Trudeau of having made "false statements" during a news conference.
During an interview with ABC's George Stephanopoulos, Trump recounted seeing Trudeau's statement following the G7 summit in Quebec, Canada, during which the prime minister promised to fight back against the US's trade restrictions. He said Trudeau's promise to follow through with tariffs on United States goods - a response to Trump's own tariffs on steel and aluminum imports from Canada, Mexico, and the European Union - would hurt the Canadian economy.
In an appearance on CNN's "State of the Union," Kudlow argued that Trudeau's critique amounted to a betrayal of the G7, as well as the U.S.
Trump called Trudeau "dishonest and weak" in very personal attacks on Twitter.
While foreign policy issues such as North Korea do not usually have much bearing on the polls, Mr Trump's outburst against Nato allies, the European Union and Canada appeared aimed at striking a chord with voters who support his America First agenda.
The editorial board criticized Trump trade adviser Peter Navarro's comment Sunday that there is a "special place in hell" for Trudeau, a remark he made after the summit ended.
"Canadians are polite, we're reasonable, but we also will not be pushed around", Mr Trudeau said.
Trump went on to say that the United States gets "unfairly clobbered" on trade despite "protecting Europe at great financial loss".
"But here's what the story is: We have been taken advantage of as a country for decades by friends and enemies both", Trump said.
Trudeau 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". Mr Trump said the move would protect domestic producers that were vital to USA security.
Trump was travelling from North America to Asia when he withdrew from a Group of Seven economic statement and insulted Canadian Prime Minister Justin Trudeau as "dishonest" and "weak".
The board noted that some of Trump's criticisms of Canada's trade policies are not significant enough to warrant a trade dispute with our neighbors to the north, and that many are exaggerated. "And if it's not fixed, we're not going to deal with these countries".
Canada is facing penalties of 25 per cent on Canadian steel and 10 per cent on aluminum, but Ries says there's still hope no tariffs will be imposed.
"Congressmen, politicians, people, you know realizing this is a bad thing-maybe that message will get to Donald Trump and we can hope he'll listen, although one might not be very confident that he'll listen to reason".
While trade is expected to dominate, Trudeau also wants to focus on gender equality and climate change.