The European Union struck back at the U.S. a day after President Donald Trump´s administration angered its major allies by slapping duties of 25 percent and 10 percent on imports of aluminium and steel.
Tariffs of 25 per cent on steel imports and 10 per cent on aluminium were due to be imposed on the EU, Canada and Mexico from 0400GMT on Friday.
Mr Morneau said Canada's government is not ready to discuss support or potential bailout packages for Canadian business sectors affected by the tariffs.
"I've been to these meetings for a long time". He has frequently threatened to withdraw the United States from the deal, but thus far he has opted to stay in while attmempting to negotiate a new deal between the member countries.
But Mr Mnuchin dismissed the narrative of "G6 plus one". "They must open their markets and take down their trade barriers! Do timber and lumber in US?"
Officials at the G7 meeting said the tariffs made it more hard for the group to work together to confront China's trade practises, especially when Beijing, like most G7 members, supports the current World Trade Organisation-based trade rules and the United States is seeking to go around them.
"The United States must, at long last, be treated fairly on Trade".
The six other G7 member nations (Canada, France, Germany, Italy, Japan and the UK) - some of America's closest allies - are all subject to the USA metals tariffs, which were imposed on the grounds of national security.
Canada's minister of foreign affairs, Chrystia Freeland, said her country would place tariffs on up to 16 billion Canadian dollars ($12.4 billion) worth of American goods, including steel and aluminum.
"The U.S.is playing a unsafe game", Malmström told reporters". "That is not Free or Fair Trade, it is Stupid Trade!"
Speaking after the meeting, Le Maire said the European Union was poised to take counter-measures against the new USA tariffs.
International Trade Minister Francois-Philippe Champagne says he doesn't want to compare the softwood lumber and metals industries, even though both key sectors of the Canadian economy face import tariffs.
Mnuchin disagreed with Le Maire.
The European Union is challenging the new tariffs with the World Trade Organization...
Mexico said that the tariffs would "distort worldwide trade" and vowed to penalize United States imports, including pork, apples, grapes, cheeses and flat steel.
Larry Kudlow, director of the National Economic Council, tells reporters Friday that he remains optimistic about the outcome of negotiations with Canada, Europe and Mexico in spite of recent escalations.
Some officials said they expected the issue of tariffs to be addressed directly by G7 leaders at their summit in the Canadian town of Charlevoix next week.