Trump also repeated an earlier proposal that USA trading partners should drop all trade barriers, including tariffs and subsidies to industries and producers in their own countries.
And Trudeau has certainly been among the leaders in that regard in recent days.
"What we have is a country here in the United States, which has the lowest tariffs in the world, lowest non-tariff barriers in the world", said Peter Navarro, a White House trade adviser, on CNN in March.
The calamitous summit ended in disarray after Trump broadsided his allies by disavowing a joint statement the USA had agreed to.
President Trump's chief economic adviser accused Canadian Prime Minister Justin Trudeau of stabbing the USA and fellow G-7 negotiators in the back with "amateurish" verbal attacks during a domestic press conference. On the other hand, another social media user said, "It looks as if Madam Merkel is teaching The Donald a lesson!"
Mr. Trudeau's office responded to Mr. Trump's tweets accusing the Canadian leader of "false statements" on Saturday, saying that the Prime Minister said nothing during the G7 summit that he had not said previously. "He did a great disservice to the whole G7", Kudlow said.
"[Trudeau] really kind of stabbed us in the back", Mr Kudlow, the director of the National Economic Council who had accompanied Mr Trump to the G7 summit said on Monday morning on CNN.
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"That's what bad-faith Justin Trudeau did with that stunt press conference".
Trump took aim at an unspecified news release issued by Canada saying, "they made nearly 100 bln dollars on trade with u.s. (guess they were bragging and got caught!)".
Shortly after Trump departed the conference for Singapore, where the president is set to meet North Korean leader Kim Jong Un, he took to Twitter to launch an unexpected tirade against the prime minister. And that comes right from Air Force One.
Friday's talks came after Trump indicated he might cut short his time at the summit, and leave before it ends Saturday.
"As far as this retaliation goes, the American press needs to do a much better job of what the Canadians are getting ready to do because it's nothing short of an attack on our political system and it's nothing short of Canada trying to raise its high protectionist barriers even higher on things like maple syrup and other goods", he said. We will stand by them and anyone who would depart from them, once their back was turned, shows their incoherence and inconsistency.
Trump pulled out of endorsing a joint communique after the G7 meet finished on Saturday with the U.S. president accusing Trudeau, the summit's chairman, of dishonesty.
But Kudlow probably didn't help the message he was sending to the Canadian leader by once referring to him as "Pierre Trudeau".