On the eve of Mr. Trump's meeting with Mr. Kim, one of the president's top trade advisers, Peter Navarro, said there was "a special place in hell" for leaders like Mr. Trudeau, accusing him of engaging in "bad-faith diplomacy" with Mr. Trump.
"The problem was that in conveying that message I used language that was inappropriate", he said.
Subsequently, Trump said he had instructed his representatives not to endorse a joint communique put out by the Group of Seven leaders after what he called Trudeau's "false statements" at a news conference.
White House trade adviser weighs in on 'Fox News Sunday'.
Both aides accused Trudeau of betraying Trump when he gave a news conference after the United States president had departed.
"That's going to cost a lot of money for the people of Canada; he learned", Mr Trump said wagging his finger.
Mr Trump's comments were in response to a reporter's question about the status of his relationship with Mr Trudeau.
"Canadians are polite and reasonable but we will also not be pushed around", he had said.
On Trump's handling of trade - where the populist president has taken major steps to enact his economic nationalist agenda - almost 80 percent of Republican voters said they approve of trade actions thus far. I really did, other than he had a news conference, that he had because he assumed I was in an airplane and I wasn't watching. "We just shook hands!'" Trump said.
"Canada does have a very big advantage over us".
The apology could ease tensions after Canada's parliament condemned the personal attack on Trudeau and as Canada's Foreign Minister Chrystia Freeland gets ready to meet with members of the Senate Foreign Relations Committee on Wednesday in Washington.
Other G-7 countries lobbied unsuccessfully at the summit for the U.S. to reverse its tariffs on imported steel and aluminium imports.
Navarro's comments came the day after Trudeau vowed not to be "pushed around" by the U.S.in response to Trump's decision to impose stiff tariffs on Canada.
And it concludes with a direct shot at Trump, calling on the House to "reject disparaging and ad hominem statements by US officials which do a disservice to bilateral relations and work against efforts to resolve this trade dispute".