He made the comments Tuesday at an event of The Wall Street Journal CFO Network in Washington.
Trump said he chose to back out of the G7 communique after watching Trudeau's closing summitnewsconference, at which he warned that Canadawould not be pushed around on tariffs - a point the Canadian prime minister had made several times before.
Trump refused to sign a joint statement over the weekend endorsing global trade rules, and accused Canada's Prime Minister Justin Trudeau of dishonesty.
The president's staff then blasted Trudeau on Sunday with economic advisor Larry Kudlow accusing Canada of stabbing the U.S.in the back.
"I see the television and he's giving a news conference about how he "will not be pushed around" by the United States". "That is how we should analyze whether Canada should continue implementing some of these supply-management policies".
"On (Trump's) comments, I'm going to stay focused on defending jobs for Canadians and supporting Canadian interests", he said. -Canada relationship in nothing but positive terms.
"I want to pay a particular tribute to Prime Minister Trudeau for his leadership and skilful chairing, which enabled us after two days of negotiation between leaders to agree actions and a shared approach on some of the most pressing challenges facing the worldwide community and our citizens", she said.
Critics of the system, which includes many people inside Canada, say it poses a barrier to the completion of ambitious free-trade deals with other countries, with the government having to give up on other areas to protect the industry during negotiations.
"Let me correct a mistake I made", he said at the conference.
"I have a good relationship with Justin Trudeau", he said.
Trump has consistently railed against what he claims are unfair trade practices by some of America's biggest trade partners, including Canada.
"It's kind of like ... if you were sitting with a friend and then out of the blue, you just punched them in the face", he said. He called on Trudeau to apologise to Trump.
"I left the [G7] meeting and I'll be honest, we are being taken advantage of by virtually every one of those countries, very, very seriously", Trump said.
Canada is America's largest trading partner, he said, adding that the USA economy would struggle to make up for Canada's absence in a tariff tit-for-tat.
Canada is the U.S.'s largest trading partner, and the USA economy would struggle to make up for Canada's absence, Heyman noted.
No panic in Singapore as summit approaches
He said that those talks "in fact are moving quite rapidly and will come to a logical conclusion more quickly than anticipated". All seven leaders had worked out a joint statement stressing the importance of a rules-based worldwide trading system.
Where will LeBron James go once he hits free agency?
I knew that question would come, but I like to be here. "I have no idea at this point", James told reporters. What either factor will mean for James' upcoming decision will be determined in the coming weeks.