It seems that Trump was referring to the War of 1812, a conflict caused by Britain and France's attempts to restrict USA trade as a part of the Napoleonic Wars.
And according to a report from the Washington Post, it's not something he's particularly looking forward to.
Bruising for a fight, President Donald Trump barreled into the Group of Seven summit Friday, eager to confront longtime USA allies over a burgeoning trade dispute and insisting Russian Federation should be brought back into the fold.
Mr. Trump, who aides say has little interest in multilateralism, twice attacked Canadian Prime Minister Justin Trudeau on Twitter on Thursday and officials concede the mood is likely to be exceptionally tense.
The US tariffs have been condemned by nations across the world, with Canada last week announcing it will impose tariffs on as much as $C16.6 billion of US steel, aluminium and other products from July 1.
Leaders dismiss Trump's national security concerns as "ridiculous".
The meeting on Friday and Saturday in Charlevoix, Quebec, will be the first chance G7 leaders have had to confront Trump in person since USA tariffs on steel and aluminum imports from Canada, Mexico and the European Union were imposed last week.
Merkel's proposal was strongly supported by other leaders at the meeting, the official said, adding that European Commission President Juncker said he was ready to invest personally in it.
Earlier Thursday, Trudeau offered Trump some qualified kudos on his North Korea peace efforts, along with French President Emmanuel Macron and Japanese Prime Minister Shinzo Abe.
"Please tell Prime Minister Trudeau and President Macron that they are charging the US massive tariffs and create non-monetary barriers", Trump wrote on Twitter Thursday.
President Trump tweeted directly at the leaders he was about to sit down with.
Friday morning he was spitting again: "Canada charges the USA a 270% tariff on Dairy Products!"
"The EU trade surplus with the USA is $151 Billion, and Canada keeps our farmers and others out". Something tells me that if Mar-a-Lago was sacked Trump would know exactly who was responsible.
"Until we can have reciprocal relationships we will not have free trade, and we will not have fair trade", Kudlow said.
Trudeau said he and Trump have disagreed over Trump's call for Canada to open up its supply management system, which protects dairy, poultry and eggs farmers, during the hard ongoing renegotiation of the North American Free Trade Agreement. "European Union treats us very unfairly, Canada very unfairly, Mexico very unfairly".
"Whether you like it or not, and it may not be politically correct, but we have a world to run", the president said.
Canada and the European Union have denounced the USA tariffs and Ottawa has proposed levies on a range of US goods next month while the European Union has pledged its own retaliatory measures.