Donald Trump has threatened to escalate a global trade war on the European Union and Canada, hours before he meets their leaders at the G7 summit in Quebec. Macron, who appeared to have built a warm relationship, said the "G6" leaders would not spark a fight at the summit.
"They are relying on the overwhelming strength of the U.S.to compel a much weaker neighbour to give in to whatever they demand, " Bothwell said.
Canadian Prime Minister Justin Trudeau said the assertion that the tariffs are a response to national security threats is "insulting and unacceptable".
G7 leaders have praised the United States president for his efforts to stabilise the Korean peninsula, but are unhappy that he pulled out of the Iran nuclear deal.
"Maybe the American president doesn't care about being isolated today, but we don't mind being six, if needs be", Macron told reporters.
The EU also filed a complaint about the USA tariffs with the World Trade Organization. "Look forward to seeing them tomorrow", Trump wrote.
Mr Trudeau has described the U.S. claim that the tariff decision was taken on national security grounds as "insulting".
Trump has also seemed less than enthusiastic about the meetings, questioning if he even needs to attend.
On the eve of the summit, Mr. Trump said little about his goals, but had messages for two of the leaders he plans to meet with.
The G7 are the United States, Canada, Japan, Britain, Germany, France and Italy.
Under Trump, the United States has abandoned its traditional role in the G-7. His predecessors pressed for freer global trade and championed a trading system that required countries to follow World Trade Organization rules.
America's closest allies braced for a showdown with President Donald Trump at the G7 summit Friday, as anger at being slapped with trade tariffs by their most powerful member threatened to split the club.
But he urged the other industrialized countries to stick together.
Already at the meeting of the finance ministers ahead of the G-7, the six non-U.S. countries released a statement raising concerns about US trade actions.
The White House tried to play down the differences with Trump's top economic adviser branding the differences as simply a family quarrel. "If it doesn't happen, we come out even better!"
America's closest allies are frustrated by Trump's imposition of steel and aluminum tariffs last week, as well as his decision to withdraw the USA from the Iranian nuclear accord and the Paris climate agreement.
But before leaving Washington, he made clear that he too has no intention of backing down on his plan to rebalance trade by imposing tariffs on steel, aluminum and other goods imported from U.S. allies. Canada is waiting until the end of the month to apply them with the hope the Trump administration will reconsider.
The Trudeau Government is scoffing at the idea of scrapping NAFTA negotiations in favour of separate bilateral trade deals. Mr Trump's singling out of Germany's vehicle sector for criticism in his gripes about the U.S. trade deficit hardly helped matters either.