Canada on Thursday shrugged off U.S. President Donald Trump's criticism that talks to modernize NAFTA were moving too slowly and made it clear that it had to keep negotiating as long as there was a chance of success.

The prospects for a quick deal to update the North American Free Trade Agreement appeared to dim on Wednesday after Trump blasted Canada's stance and threatened to impose tariffs on cars imported from its northern neighbor.

"The Americans are finding that the negotiations are tough because Canadians are tough negotiators, as we should be," Canadian Prime Minister Justin Trudeau told reporters on the way into a regular weekly Cabinet meeting in Ottawa.