"My job was to send a signal of strength", he said.
Asked if he was apologizing for the comments, Navarro said, "yeah, absolutely".
He had said there was a "special place in hell" for Mr Trudeau for going against US President Donald Trump. He later called Trudeau "very dishonest & weak" and refused to sign a joint statement following negotiations.
"And that's what bad-faith Justin Trudeau did with that stunt news conference".
Trump and his inner circle were irked by Justin Trudeau's comments to media that Canada would not be "pushed around" by the USA and will respond in kind to tariffs slapped on steel and aluminum on the "insulting" grounds of national security.
Canadian Foreign Minister Chrystia Freeland responded to the White House assault by saying ad hominem attacks were not helpful, that Canada would retaliate to U.S. tariffs in a measured and reciprocal way and that Canada would always be willing to talk.
If the US imposes a 25 percent tariff on those exports, suddenly they don't make much economic sense, said Kristin Dziczek, vice president of industry, labor and economics at the Center for Automotive Research in Ann Arbor, Michigan.
"It's very unfair to our farmers, and it's very unfair to the people of our country", Trump said Tuesday in Singapore. "That's what weak, dishonest Justin Trudeau did, and that comes right from Air Force One".
"He's giving a news conference about how he will not be pushed around by the United States".
Trudeau, who had said at the news conference that Canada would retaliate for new US tariffs, didn't respond to questions about Trump when the prime minister arrived at a Quebec City hotel Sunday for meetings with other world leaders.
"There's a lot of concern being expressed about where this might go", Easter said as he entered the House of Commons.
Navarro took a decidedly more conciliatory tone Tuesday, but still asserted that Trudeau had committed a "breach of protocol" that the Trump administration considered "inappropriate". "Canadians - we're polite, we're reasonable - but we also will not be pushed around". The vehicle tariffs could apply to all countries, including Nafta partners Mexico and Canada, the two biggest exporters of autos to the U.S. "He'll learn, he can't do that", Trump said.
The criticism was echoed by White House economic adviser Larry Kudlow, who joined Trump at the G7 meetings.
"[Trump] wants to move all of that manufacturing back to the States, [but] we don't have people to actually do this work", Heyman said.