Trump had previously criticized both leaders concerning trade issues with the United States.
Trump also told reporters Friday he would favor Russia's re-admittance to the Group of Seven. Russia was expelled from the group in 2014 after it annexed Crimea from Ukraine, a move that was condemned by the coalition.
"Russia should be in this meeting. Why are we having a meeting without Russia being in the meeting?" Trump asked reporters in Quebec. "It may not be politically correct, but we have a world to run.
"They should let Russia come back in. Because we should have Russia at the negotiating table."
Friday's talks came after Trump indicated he might cut short his time at the summit, and leave before it ends Saturday.
The White House said Trump could leave before discussions on climate change, energy policy and oceans to get a jump on his trip to Singapore for his meeting Tuesday with North Korean leader Kim Jong Un.
Trump told reporters Friday it is possible he will leave early, but not certain.
Trump said Friday he's "looking forward to straightening out unfair trade deals with G7 countries" at the summit.
Macron and Trudeau have presented a united front against what they say are protectionist trade measures by Trump -- particularly his decision to impose tariffs on steel and aluminum imports from Canada, Mexico and the European Union.
Other G7 leaders, including May and Merkel, have also spoken out against the U.S. tariffs.
I am heading for Canada and the G-7 for talks that will mostly center on the long time unfair trade practiced against the United States. From there I go to Singapore and talks with North Korea on Denuclearization. Won't be talking about the Russian Witch Hunt Hoax for a while!- Donald J. Trump (@realDonaldTrump) June 8, 2018
On Thursday, Trump took aim at Trudeau and Macron, accusing them of benefiting from one-sided trade arrangements with the United States.
"Prime Minister Trudeau is being so indignant, bringing up the relationship that the U.S. and Canada had over the many years and all sorts of other things...but he doesn't bring up the fact that they charge us up to 300 percent on dairy -- hurting our Farmers, killing our Agriculture!" Trump tweeted.
Earlier on Twitter, Macron said six of the seven G7 countries "do not mind" signing an agreement if need be -- essentially isolating the United States.
"The American President may not mind being isolated, but neither do we mind signing a 6 country agreement," Macron said.
Canada hosts this year's G7 in Quebec. France will host next year and the United States in 2020.