He blamed past world leaders, including past presidents, for that situation, but said the current crew - including Prime Minister Justin Trudeau - now know that the "gig is up".
He told the G7 leaders during the summit that the U.S. wanted a quick end to trade practices that he said have led to an exodus of American companies and jobs to other countries.
He continued: "What we did this weekend was come together and roll up our sleeves and figure out consensus language that we could all agree to on a broad range of issues". Prime Minister Justin Trudeau did not wait for the USA president to kick off the meeting in La Malbaie, Quebec.
President Donald Trump leaves after holding a press conference ahead of his early departure from the G7 Summit on June 9, 2018 in La Malbaie, Canada. "Very dishonest and weak", Trump said.
Earlier on Saturday, Trump told reporters it would be "very easy" to make the case for tariffs on auto imports using the rationale that they threaten national security.
Trump cited progress on reaching an agreement on the North American Free Trade Agreement with Canada and Mexico, saying the final outcome would lead either to an improved trade deal or separate pacts with the two USA neighbors.
"It would be with regret, but it would be with absolute certainty and firmness that we move forward with retaliatory measures on July 1 applying equivalent tariffs to the ones that the Americans have unjustly applied to us", Trudeau said.
Speaking in a solo press conference from the resort town of La Malbaie in Quebec, the president said that for too long, US trade has suffered from "bad" trade deals agreed to by past USA presidents.
"The relationship that I've had with these leaders is great.so you can tell that to your fake friends at CNN", he said after a reporter from that network asked about the state of the relationship with these close USA allies.
"In this environment, above all we always have to stay polite, stay productive and try to convince (them) to keep the United States on board because they are our historical ally and we need them", Macron told a news conference with Trudeau in Ottawa. Japanese Prime Minister Shinzo Abe - a veteran of seven G7 leaders' meetings - said the Charlevoix summit featured heated exchanges, the likes of which he has never seen. He added that he did not blame G7 leaders for the "unfair" trade deals.
Apparently reveling in a rift that threatens to spiral into a trade war, Trump stirred the pot by declaring before the talks began that he would like to see Russian Federation re-admitted to the club.
"We are focused on everything we accomplished here at the G7 summit", the statement, released by Cameron Ahmad, said. "But he doesn't bring up the fact that they charge us up to 300% on dairy - hurting our Farmers, killing our Agriculture", the U.S. president said. The statement had been published online before Trump commented.
"You want a tariff-free - you want no barriers, and you want no subsidies", he said. The United States pays enormous tariffs on dairy.
Merkel has said that it may be "more honest" for the G7 to avoid coming up with a joint statement at the end if it means compromising its principles.