Fox Business reporter Susan Lee asked Trump in a press conference at the United Nations General Assembly in NY.
"Yeah, I did", he told a news conference in NY when asked by a reporter whether he had rejected a one-on-one meeting with Trudeau. "That's the mother lode, that's the big one".
A spokeswoman for the Canadian prime minister denied that he had requested any such meeting, but Trump's comments on Wednesday marked a new low in relations between the two leaders.
President Trump said the U.S.is not getting along with the Canadian negotiators "at all".
"We're unhappy with the negotiations and the negotiating style from Canada", he said.
Trump, during the news conference, reiterated his longstanding grievances against NAFTA and job losses, saying the trade pact had been 'great for Canada, great for Mexico, very bad for us'.
Trump did not say what representative he meant.
A senior Canadian official told CBC News the Trump comments should be seen in the context of the continuing negotiations.
President Donald Trump has informed Congress he intends to sign a new deal, with or without Canada, by late November before Mexico's new president takes office.
McNaughton said he had jokingly told Robert Lighthizer, the U.S. Trade Representative, that he would schedule a root canal operation after their next session, "just to make me feel better".
Asked if a good deal is possible, even if the USA moves on this week with Mexico alone, Trudeau said, "We will keep working on a broad range of alteratives".
On the other hand, should Canada decide to join the agreement, the Canadian dollar could go significantly stronger. The U.S. had been pressing to reach a deal that included Canada as well, but talks are expected to continue anyhow. "Under our deal, not going to happen anymore".
Trump has used an obscure "national security" provision of USA trade law to impose tariffs on imports of Canadian steel and aluminum.
Meanwhile, analysts with JPMorgan Chase predict that if the United States and Mexico proceed with the deal alone, the Canadian dollar would be gravely impacted.
Trump has repeatedly threatened to cut Canada out of a trade agreement if the country does not agree with his terms. "But it will probably or possibly be just USM", he said suggesting it will likely only include the USA and Mexico.