Transcript for Trump and allies trade barbs at G7

At the same time president trump is on a mission of peace, he's attacking America's closest allies. Singly out just Justin Trudeau and taking on the G 6 countries for deals trade. Here's ABC's chief global affairs correspondent ma Raddatz. Reporter: Even as he was preparing to sit down with America's fiercest foe, president trump launched a new volley of attacks on our closest allies. "Sorry, we cannot let our friends, or enemies, take advantage of us on trade anymore," he tweed. Barely 48 hours ago the president was touting his ties to the g7 countries. Angela and Emmanuel and Justin I would say the relationship is a ten. Reporter: But things ickly turned dark, trump refusing to budge on his plans to impose stiff tariffs on aluminum and steel from Canada and other allies. Canadian prime minister Justin Trudeau vowing to retaliate with tariffs on American goods. Canadians, we're polite, we're reasonable, but we also will not be pushed around. Reporter: The president went ballistic, calling Trudeau "Dishonest and weak," refusing to sign the traditional g7 statement of solidarity. His advisors goingven further. There's a special place in hell for a foreign leader that engages inad faith diplomacy with president Donald J. Trump and then tries to stab him in the back on the way out the door. Reporter: They accused Trudeau of trying to undermine the North Korea summit. The predent is not going to let a Canadian prime minister push him around. Kim must not see American weakness. Reporter: Frocanada, a measured response. Canada does not believe that ad hominem attacks are a particularly appropriate or useful way to conduct our relations. Reporter: And in Germany, chancellor Angela Merkel calling out trump's words as "Sobering and a little depressing." Martha Raddatz back with us tonight in Singapore. Secretary Pompeo was pressed if he agreed what the president said about Justin Trudeau. He often said there are irritants in the relationships. There areirritants, but very rarely name calling from a president of the United States to our allies. We're here for this historic summit. That doesn't going away. Thank you, Maha. Stay right here for ABC wn president trump and Kim Jong-un meet.

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