In the communique announced by Canadian Prime Minister Justin Trudeau, the group of major industrial nations - Canada, the U.S., the UK, France, Italy, Japan and Germany - agreed on the need for "free, fair, and mutually beneficial trade" and the importance of fighting protectionism.
German Chancellor Angela Merkel and IMF Managing Director Christine Lagarde wait for the arrival of President Donald Trump to the Gender Equality Advisory Council breakfast during the G-7 summit, Saturday, June 9, 2018, in La Malbaie, Quebec Canada.
Earlier in the day, Trudeau said during a news conference that Canada will "move forward with retaliatory measures" on July 1 in response to the Trump administration's decision to impose tariffs on steel and aluminum imports from Canada, the European Union and Mexico. "With one country we have $375 billion in trade deficits".
European officials said Trump had tried to water down the language in the draft final summit communique on the WTO and rules-based trade.
"If they retaliate, they're making a mistake", he warned, insisting that the United States has much less to lose than its partners in the event of world trade breaking down. "I think it will be very positive", Trump said on Friday, without giving details.
"The United States has been taken advantage of for decades and decades", he continued, describing America as a "piggy bank that everyone keeps robbing". "Our tariffs are in response to his of 270 per cent on dairy!"
Trump's latest tweets follow a number of pre-G7 Summit tweets in which he sparred with both Trudeau and French President Emmanuel Macron.
Donilon, who served under former president Barack Obama, was responding to a clip in which Trump made the case for including Russian Federation.
Trump attacked Canadian Prime Minister Justin Trudeau in a set of tweets sent after departing the summit ahead of schedule.
Meanwhile, the European Union - the world's largest trading bloc - announced last week it would impose retaliatory tariffs on the USA beginning in July, over Washington's duties on steel and aluminum imports from Europe.
The trade spat dominated the meeting, with Canadian and European leaders threatening retaliatory duties in response to the USA levies. And tariffs are going to come way down, because people can not continue to do that.
Donald Trump says he wants to make a deal on NAFTA, and he's open to working with the current pact or striking separate agreements with Canada and Mexico - as long as they agree to renegotiate every five years.
He left the summit early to travel to Singapore for a landmark meeting with the North Korean leader Kim Jong-un to try to persuade him to give up the country's nuclear weapons.
"The nature of the debate we had was rather appeasement and it stopped the escalation in terms of behavior", Macron, who had exchanged terse Twitter messages with Trump in the run-up to the summit, told reporters.
Investors are also concerned about the future of the North American Free Trade Agreement, which Trump has threatened to terminate.