The top White House economic adviser accused Canada's prime minister on Sunday of betraying President Donald Trump with "polarizing" statements on USA trade policy that risked making the American leader look weak on the eve of a historic summit with North Korea.
White House chief economic adviser Larry Kudlow, a former television personality who was described by one commentator as an "insufferable Wall Street hack", echoed Navarro's vitriolic rhetoric in an interview with CNN's Jake Tapper on Sunday, calling Trudeau "amateurish" and "sophomoric".
US President Donald Trump continued to excoriate his Group of 7 summit allies in a series of tweets from Singapore, where he is due to meet North Korean leader Kim Jong Un in a historic summit Tuesday.
After President Trump left, from Air Force One, he rage-tweeted an attack on Canadian Prime Minister Justin Trudeau, and announced the USA was revoking its agreement to accept the joint statement of the G-7 members.
A few hours earlier, Trudeau had told reporters that all seven leaders had come together to sign the joint declaration.
"In a matter of seconds, you can destroy trust with 280 Twitter characters", German Foreign Minister Heiko Maas said when asked about Mr Trump's U-turn, adding it would take much longer to rebuild lost trust.
Lewis Hamilton finishes fourth in 2018 Canadian Grand Prix qualifying
Behind the leaders, there was chaos when Williams's Canadian Lance Stroll squeezed Toro Rosso's Brendon Hartley into the wall. The day was less positive for two-time world champion Fernando Alonso , who was celebrating his 300th Formula One race.
Canadian Prime Minister Justin Trudeau has vowed retaliatory action next month over United States tariffs on steel and aluminium.
France and Germany both reacted with anger to Mr Trump's decision.
Trudeau called the fact that the USA had based the tariffs on a national security reason "kind of insulting".
"It is not something we relish doing, but it is something that we absolutely will because Canadians, we're polite, we're reasonable, but we also will not be pushed around", Trudeau said.
U.S. President Donald Trump's Twitter tirade against Prime Minister Justin Trudeau following the G7 is sparking promises of support from some of Trudeau's political rivals as well as calls for calm from foreign diplomats and experts.
"If a deal isn't made, that would be a very bad thing for Canada and it would be a very bad thing for Mexico", Trump said. And what did Trudeau do as soon as the plane took off from Canadian airspace?
Anthony Bourdain's mother says his body is stuck in France
Bourdain's partner, the Italian actress Asia Argento , 42, said: "Anthony gave all of himself in everything that he did". I feel like I've stolen a auto - a really nice vehicle - and I keep looking in the rear-view mirror for flashing lights.
Prime Minister Justin Trudeau, in a statement: "We are focused on everything we accomplished at the G7 summit". On Friday, he reiterated a threat to quit the existing pact altogether if he doesn't get his way, only days after Kudlow said Trump wouldn't walk away.
Peter Navarro watches as President Donald Trump speaks before signing Section 232 proclamations on steel and aluminum imports in the Roosevelt Room of the White House on March 8, 2018 in Washington, D.C.
Larry Kudlow and Peter Navarro, trade advisors to Trump, went on national television on Sunday to criticize the Canadian prime minister for "betraying" the USA president. "The prime minister said nothing he hasn't said before - both in public, and in private conversations with the president". "We make our commitments and keep them".
"Let's be serious and worthy of our people", a statement from the French presidency said.
In recent weeks, trading partners of the USA have criticised new tariffs on steel and aluminium imports imposed by the Trump administration.
The outburst against Trudeau, and by association the other G7 members, is only the latest incident in which Trump has clashed with America's closest allies, even as he has had warm words for autocrats like Kim and Russia's Vladimir Putin.
Putin says ready to meet Trump 'as soon as' Washington is ready
The United States and Russia's relationship has remained a big part of Trump's presidency since the 2016 election. Putin said that Washington's decision to exit the agreement could "destabilise the situation" in the region.
On June 1, the USA imposed a 25 per cent tariff for steel and 10 per cent for aluminium on imports from the European Union (EU), Canada, and Mexico.