WASHINGTON — President Trump left America’s closest allies in a state of shock and outrage Sunday after a verbal barrage against Canadian Prime Minister Justin Trudeau, who had just hosted Trump and other leaders from the Group of Seven industrial nations.

Trump’s rhetorical assault on Trudeau, characteristically delivered on Twitter, was echoed by two top White House advisers who took to the Sunday talk shows to go after the leader of the United States’ neighbor to the north.

The bizarre aftermath of the G-7 summit in Quebec was a political calculation, meant to show muscularity in advance of the historic summit in Singapore with North Korean leader Kim Jong Un, one of those advisers acknowledged Sunday. There has rarely been such a coordinated and acerbic series of attacks by White House advisers aimed at a U.S. ally, revealing the extent to which Trump possibly felt slighted by Trudeau as he left for his North Korea talks.

“POTUS is not gonna let a Canadian prime minister push him around,” Trump’s chief economic adviser, Larry Kudlow, said on CNN’s “State of the Union.” “He is not going to permit any show of weakness on the trip.”

CNN host Jake Tapper picked up on the implication, saying this was about North Korea.

“Of course it was, in large part,” Kudlow said. “Kim must not see American weakness.”

Another of Trump’s top advisers, Peter Navarro, intensified the attack on Trudeau in an interview on “Fox News 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. “And that’s what ‘bad faith’ Justin Trudeau did with that stunt press conference.”

Trump took umbrage at remarks Trudeau made Saturday at a news conference after the G-7 summit. Trudeau’s comments were pointed but not surprising. He and other G-7 leaders have for weeks been critical of Trump’s decision to impose tariffs on steel and aluminum from their countries. Canada and other countries could potentially retaliate with tariffs of their own, leading to a trade war.

Trudeau spent most of his news conference trying to play down divisions between the United States and the six other members of the G-7. As the host of the summit, Trudeau would not have wanted the four-decade-old G-7 to collapse in his country. He said he wanted to work with U.S. negotiators on trade deals and criticized tariffs imposed by Trump. He added, “Canadians, we’re polite, we’re reasonable, but we also will not be pushed around.”

Those were fighting words for Trump, who on Twitter accused Trudeau of “false statements” and of being “very dishonest & weak.” He didn’t specify what comments he felt were false. Trump wrote that he had ordered his aides to withdraw the United States’ endorsement of a joint communique that he and the other G-7 leaders had agreed to.

Trump also said he was going to pursue an investigation that could push up tariffs on foreign auto imports and appeared to tie that to what he viewed as unfair dairy tariffs imposed by Canada.

Kudlow repeatedly charged Trudeau with the “betrayal” of Trump and other leaders of the G-7.