The British leader echoed disappointment from other leaders that President Donald Trump first agreed to a communique for "free, fair and mutually beneficial trade" and the reduction of "tariff barriers", but later tweeted he wouldn't endorse the deal.
Canadian Prime Minister Justin Trudeau said his country "will not be pushed around on trade matters." and called US tariffs on Canadian steel and aluminum "insulting".
"We won't let ourselves be ripped off again and again".
In return, Mr Trump made the French president his guest at his first White House state dinner, after which the USA president said of his visitor: "I like him a lot".
The captions reads: "Day two of the G7 summit in Canada: spontaneous meeting between two working sessions".
Trump's announcement on Twitter, after leaving the Group of Seven summit in Canada early, that he was backing out of the joint communique torpedoed what appeared to be a fragile consensus on a trade dispute between Washington and its top allies.
Asked if she was concerned that Trump could retaliate against European Union counter-measures by imposing tariffs on cars, Merkel said: "First of all, we'll try and see if we can prevent this".
The US president came under fire at the contentious G7 summit of leading economic powers for his "America First" protectionist drive.
German reporter who exposed Russia doping'won't be at World Cup
German Chancellor Angela Merkel said Sunday (10 June) she was more open to French President Emmanuel Macron's plans to reform migration and defence policy in Europe than his hopes to bolster the euro.
Emmanuel Macron has warned Donald Trump about "fits of anger" after the U.S. president refused to endorse a joint communique of G7 leaders.
Officials from Justin Trudeau's team also shared an image of the Canadian PM and summit host leader being presented with work by Prime Minister Theresa May, Mr Macron and Mrs Merkel, while an uninterested Mr Trump stares into space.
In case ya missed it, the leaders of Germany, Canada, Japan, United States, France, Italy, and the United Kingdom have come together to talk global issues.
That statement had sought to overcome deep disagreements, notably over trade.
Germany, Europe's top economy, finds itself in the sights of the United States president due to its large trade surplus and defense spending criticized as too low.
Trump cited unfair trade and tariffs from Canada, a longtime USA ally, as one of the reasons he refused to back the joint statement. Asked by reporters whether he would relent on tariffs, Trump looked at Merkel and said: "I don't know".
Dennis Rodman: I got call saying Trump was proud of me
The basketball Hall-of-Famer said that he had received threats on his life after returning from North Korea in 2014. For those of you who don't know, Dennis has formed quite a strong relationship with Kim Jong Un and Donald Trump .
The Red Arrows wish England luck ahead of World Cup
Harry Kane says England will be "aggressive and brave" during this summer's World Cup in Russian Federation . We are our own team, we have our own identity and we just have to look forward and enjoy it.
Monday forecast: HOT with severe storms this evening
We will not be completely rain free, but more of us than not should be able to get out and get some outdoor chores taken care of. Temperatures will only fall into the lower 70s tonight before rebounding into the upper 80s to low 90s again Sunday afternoon.