Macron on Thursday announced he would meet UK Prime Minister Theresa May, German Chancellor Angela Merkel and Italian PM Giuseppe Conte at 10.30am on La Malbaie, in the French-speaking Canadian province of Quebec.
European Commission president Jean-Claude Juncker and European Council president Donald Tusk would also attend, he said.
Having met Canadian leader Justin Trudeau, Macron said that the leaders of several of the world's leading economies should not be afraid of failing to reach agreement with the US, following Trump's imposition of tariffs and threat of sanctions against companies trading with Iran, following the US withdrawal from the multilateral nuclear deal with the Islamic Republic.
The disagreements would allow the "reforging of Europe", he said, and would "at least strengthen agreement between the six" at a summit that has been nicknamed the "G6 + 1".
After meeting Macron, Trudeau described Trump's claim that the tariffs were needed for the US's security as "laughable".
Macron warned that they would be "counterproductive" for the US's own economy and jobs.