Trudeau had announced that the G7 members - Canada, France, Germany, Italy, Japan, the United Kingdom and the USA - had agreed upon a joint communiqué, or formal statement, after a hard week on trade issues.
The top White House economic adviser accused Canada's prime minister on Sunday of betraying President Donald Trump with "polarizing" statements on US trade policy that risked making the American leader look weak on the eve of a historic summit with North Korea.
Trump, who was headed to Singapore for a summit with North Korean leaders, criticized Trudeau for making "false statements" at a news conference held after Trump had left Canada. Mr Kudlow suggested Mr Trump saw Mr Trudeau as trying to weaken his hand before that meeting, saying the president would not "let a Canadian prime minister push him around".
In scenes, remarks, and tweets that are unprecedented in the diplomatic world, Trump brought the US-led alliance of advanced economies close to a rupture, refusing to sign a joint communique with the group and calling Trudeau a "dishonest liar" - all over the contentious issue of trade tariffs on which he feels the USA has been unfairly treated.
Trudeau announced on Saturday that all G7 members had endorsed the joint communique; however, he noted that the USA tariffs are "insulting" and Canada "will not be pushed around".
Earlier, Mr Trudeau had spoken of retaliatory measures that Canada would take next month in response to Mr Trump's decision to slap tariffs on steel and aluminum imports from Canada, Mexico and the European Union. But that didn't stop the Twitteratis from drawing inferences about the kind of "power dynamics" was at play at the Summit, where Trump seemed to not be in sync with the rest of the U.S. allies, as was perhaps evident by his decision to not endorse the joint statement.
President Trump and PM Lee last met in October 2017, during Mr Lee's visit to Washington DC at Mr Trump's invitation.
Trump complained on Sunday that he had been blindsided by Trudeau's criticism of his tariff threats at a summit-ending news conference.
"Canada does not believe that ad hominem attacks are a particularly appropriate or useful way to conduct our relations with other countries", said Canadian foreign affairs minister Chrystia Freeland, according to the Toronto Star.
"We don't want to stand alone in the world", Feinstein said on CNN's State of the Union.
Trudeau, who announced that the G7 had issued a joint communique, had to suffer the wrath of Trump.
Navarro said Trump "did the courtesy to Justin Trudeau to travel up to Quebec for that summit".
Merkel said the G7 leaders had agreed to review their trade ties and assess the scope of existing tariffs in order to avoid further trade barriers.
The president concluded his tweetstorm by saying, "Sorry, we can not let our friends, or enemies, take advantage of us on Trade anymore". She also doubted if the United States leader still has what she called "the spirit of G7".
"There are always irritants in relationships", Pompeo said, adding that without partners like Canada, "we wouldn't be in this place, we wouldn't have this diplomatic opportunity" with the North.