"The problem was that in conveying that message I used language that was inappropriate", he said. "That was my mistake, those were my words".
The Trump administration recently slapped tariffs on steel and aluminum imports from Canada, Mexico and the European Union, prompting dollar-for-dollar retaliatory action from Prime Minister Justin Trudeau's government.
"I know it didn't look friendly", Trump said.
"As the former US ambassador to Canada I am calling on Peter Navarro to formally and publicly apologize to @JustinTrudeau and more importantly the Canadian people for his insulting and inappropriate remarks", tweeted Bruce Heyman, who was ambassador under former president Barack Obama.
Russian President Putin Welcomes President Trump's Call to Join G7 Coalition
The two leaders then attended an ice hockey between the youth teams of Russian Federation and China. Iranian President Hassan Rouhani has warned about the threat U-S unilateralism poses to the world.
Trump, meanwhile, continued to be critical of Trudeau at a news conference in Singapore following his summit with North Korean leader Kim Jong Un. "It's kind of insulting".
Canadian Foreign Minister Chrystia Freeland responded to the White House assault by saying ad hominem attacks were not helpful, that Canada would retaliate to USA tariffs in a measured and reciprocal way and that Canada would always be willing to talk.
Alberta's economic development minister says Canada has to stand up to U.S. President Donald Trump's trade threats.
Trump again presented the USA as the victim of unfair trade deals during the interview with ABC on Tuesday. Kudlow explained on CNN that the administration was lashing out at Trudeau to show Kim that Trump was not weak. "That was a mistake".
As for Trump's own response, he predicted that Trudeau's remarks are going to cost Canada "a lot of money".
"I will always protect Canadian workers and Canadian interests", Mr Trudeau said.
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Putin and his aides say it is an indispensable tool to gauge public sentiment and learn about people's real problems. He added, however, that he could pull them out of the country quickly if necessary. "Total nonsense.
White House trade adviser weighs in on 'Fox News Sunday'.
Dairy Farmers of Canada president Pierre Lampron, which represents Canada's roughly 12,000 dairy producers, fired back Monday by blasting Trump's "personal attacks on our prime minister" and defending its supply-managed system.
The motion also said the House rejects "disparaging ad hominem statements by US officials which do a disservice to bilateral relations and work against efforts to resolve this trade dispute".
Trump and Kim shook hands and posed for photos before their almost 40-minute one-on-one conversation behind closed doors.
The U.S. helped negotiate the joint communique and was "very close to making a deal with Canada" on the North American Free Trade Agreement, Kudlow said.
"It'll hurt the U.S.as much as it'll hurt Canada", said Dias, who pointed out that the majority of parts in Canadian-built vehicles come from the U.S.
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Before the game, Cavs coached Tyronn Lue was asked to explain the home-road discrepancy. But we've got to come out and got to play 48 minutes".