Peter Navarro, a trade adviser to President Donald Trump, escalated the White House's rebuke of Canadian Prime Minister Justin Trudeau, calling him weak and dishonest on Sunday.
"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 on "Fox News Sunday."
He continued, "And that's what bad faith Justin Trudeau did with that stunt press conference. That's what weak, dishonest Justin Trudeau did, and that comes right from Air Force One."
Navarro's comments added to the White House's continued criticism of Trudeau, who said after Trump left the G7 summit that Canada would impose retaliatory measures to answer Trump's tariffs and warned that Canada would not be "pushed around."
"I will always protect Canadian workers and Canadian interests," Trudeau said.
The comments from Trudeau prompted Trump to criticize the Canadian leader on Twitter and decline to endorse the G7 communique.
Larry Kudlow, Trump's top economic adviser, took things further Sunday morning, saying on CNN's "State of the Union" that Trudeau's comments amounted to a "betrayal."
Canadian Foreign Minister Chrystia Freeland said on Sunday in response to questions about Kudlow and Navarro's comments that she is thankful she is "not responsible for explaining the reasoning behind any comments made by the officials of any foreign government."
Freeland touted Canada's retaliatory measures several times as she referred to Trump's tariffs on Canadian steel and aluminum as "illegal and unjustified" and disavowed "ad hominem attacks."
"Canada is very clear," she said. "We are very measured. We used fact-based arguments."
Freeland said of the US tariffs, "The national security pretext is absurd and frankly insulting to Canadians, the closest and strongest ally the United States has had. We can't pose a security threat to the United States, and I know that Americans understand that. So, that is where the insult lies."
European Council President Donald Tusk used Navarro's phrasing in a tweet backing Trudeau later Sunday.
"There is a special place in heaven for @JustinTrudeau. Canada, thank you for the perfect organisation of G7!" Tusk tweeted.
Navarro, in his interview on Fox, said Trump "did the courtesy to Justin Trudeau to travel up to Quebec for that summit" and that Trump had "bigger things on his plate" than the G7 meeting, namely his planned meeting with North Korean leader Kim Jong Un in Singapore.
"He did him a favor," Navarro said. "And he was even willing to sign that socialist communique, and what did Trudeau do as soon as the plane took off from Canadian airspace? Trudeau stuck our President in the back."
Asked if these were statements from the President, Navarro said they were his words, but that they reflected "the sentiment that was on Air Force One."