Trump then took aim at Canada's dairy supply management system, which he said is hurting Wisconsin dairy farmers by charging them tariffs of up to 300 per cent.
"We're very unhappy with the negotiations and the negotiating style of Canada - we don't like their representative very much", Trump said.
In his response, Trump also complained about Canada's negotiators and appeared to make a specific reference to Foreign Affairs Minister Chrystia Freeland - who has been Trudeau's NAFTA point person since talks began 13 months ago.
Earlier Wednesday, Canada's USA envoy David MacNaughton, who has taken part in the Washington talks alongside Foreign Affairs Minister Chrystia Freeland, pegged the likelihood of a new trade deal by Sunday's congressional deadline at a "five" on a scale of one to 10.
Talks have become increasingly hostile.
He also said he is still willing to put a "motherload" tariff on Canadian auto parts, which could affect $200bn of Canadian exports to the US.
"His tariffs are too high and he doesn't seem to want to move".
"Canada's not making concessions in areas we think are essential", Lighthizer continued.
He did not rule out the possibility of a deal, but made it clear he had little interest in compromising.
Both the USA and Mexico have said they will press ahead with the bilateral accord they reached last month, with or without Canada. 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".
"I must be honest with you, we're not getting along at all with their negotiators", Trump said.
The two sides are still far apart on major issues such as how to settle disputes and US demands for more access to Canada's protected dairy market.
Mexico and the US sealed a new trade deal after the threat of sanctions forced both sides into an agreement.
All three countries have pushed to reach an agreement by October 1 so it can be signed by Mexico's outgoing president before he leaves office December 1, while complying with a USA law that says the text of a new trade deal must be released 60 days before it's signed.
"We will keep working as long as it takes to get to the right deal for Canada", Trudeau earlier told reporters at the United Nations.
"The president's objective is to have deals with Mexico and have a deal with Canada, stated Treasury Secretary Steve Mnuchin". A spokesman for the U.S. Trade Representative's Office declined to comment. Officials in the PMO insisted no such request had been made, given already close contact with the White House.
"Canada will come along", Trump said, before again threatening to tax Canadian auto imports if the Trudeau government didn't come around.
Relations between the two neighbours have been strained since Trump assailed Trudeau at the G-7 meeting in June, calling him a "weak" and "dishonest" back-stabber.