Sunday on CNN’s “State of the Union,” President Donald Trump’s top economic adviser Larry Kudlow explained why Trump did not sign on to the G7 communique and his subsequent reaction to Canadian Prime Minister Justin Trudeau.

En route to Singapore for a summit with North Korean dictator Kim Jong Un, Trump tweeted his disapproval of Trudeau and suggested what the Canadian leader had done contradicted the goodwill at the G7.

Based on Justin’s false statements at his news conference, and the fact that Canada is charging massive Tariffs to our U.S. farmers, workers and companies, I have instructed our U.S. Reps not to endorse the Communique as we look at Tariffs on automobiles flooding the U.S. Market! — Donald J. Trump (@realDonaldTrump) June 9, 2018

PM Justin Trudeau of Canada acted so meek and mild during our @G7 meetings only to give a news conference after I left saying that, “US Tariffs were kind of insulting” and he “will not be pushed around.” Very dishonest & weak. Our Tariffs are in response to his of 270% on dairy! — Donald J. Trump (@realDonaldTrump) June 9, 2018

“It was a betrayal,” Kudlow said of Trudeau.

“He really kind of stabbed us in the back,” he added.

“President Trump played that process in good faith,” Kudlow said. “So, I ask you: He gets up in the airplane and leaves, and then Trudeau starts blasting him at a domestic news conference? I am sorry, that’s a betrayal. That’s a double cross.”

Kudlow explained the importance of Trump offering a stern response to Trudeau given the upcoming Singapore summit.

“Kim must not see American weakness,” he said. “This is a case where Trudeau — it was like, I don’t know, pouring collateral damage on the whole Korean trip. That was a part of Trudeau’s mistake. Trudeau made an error. He should take it back. He should pull back on his statements, and wish President Trump well in the Korean negotiations.”

Follow Jeff Poor on Twitter @jeff_poor