Peter Navarro says his job was to send a "signal of strength" after Trudeau's post-G7 news conference sent the USA president into a fit of pique that threw the summit into disarray.
"I'm not sure what activity he's asking me to undertake with either", quipped May.
"He'll learn that's going to cost a lot of money for the people of Canada".
Peter Navarro, a White House trade adviser, has apologised after saying "there's a special place in hell" for Canadian Prime Minister Justin Trudeau, who is in a trade dispute with President Donald Trump.
"In conveying that message I used language that was inappropriate and basically lost the power of that message", he said.
"I know it didn't look friendly", Trump said.
Navarro condemned Trudeau following the Canadian leader's news conference after his summit meeting with Trump and other world leaders from the Group of Seven.
Freeland said she had a "good conversation" Sunday with US Trade Representative Robert Lighthizer, and that the pair would try to meet in Washington this week.
"It would potentially bring down the entire economy and push it into a recession", he said.
As Business Insider's Michelle Mark reported, the summit ended in disarray: Late Saturday, US President Donald Trump tweeted that the US would not endorse the joint statement from the summit.
The United States has alienated Canada and other allies by imposing tariffs on steel and aluminum imports, arguing that they pose a threat to USA national security. "And that's what bad-faith Justin Trudeau did with that stunt news conference".
Navarro's willingness to walk back his outburst marked a departure from the Trump administration's never-say-you're-sorry approach to political crises.
In Vermont, where Trump is particularly unpopular, a few choice words from the president won't keep people away from a popular weekend getaway on either side of the border, says one keen observer.
"I have had a good relationship with Justin and I think I have a very good relationship with chairman Kim right now", Trump said."(Trudeau) learned. You can't do that. Trump's steel tariffs and threats to tax auto imports, among other protectionist policies, have strained relations with America's closest allies, including Canada, with whom the administration has been struggling to re-negotiate NAFTA.
Then, he went on about how massive trade surpluses were not fair to the American people and how the United States pays almost the full cost of North Atlantic Treaty Organisation which protects "many of these same countries that rip us off on Trade" and remarked, "Change is coming". "And it won't even be tough". They take effect July 1.
"We've got to look at what supports are available to ensure that if their jobs, their livelihoods are compromised, what can the government do to support these folks".