The fourth round of talks resume Wednesday.
Mexico's foreign relations secretary, Luis Videgaray, said Tuesday his country won't accept "limited, managed trade", an apparent reference to demands for higher USA and regional content rules on products like auto parts.
"I happen to think that Nafta will have to be terminated if we're going to make it good. It's possible we won't be able to make a deal and it's possible that we will", Trump said, noting the close relations between the two countries and leaders.
Trudeau also said that Canada was well aware of Trump's unpredictability.
It wasn't clear whether the change in the prime minister's NAFTA message was a direct result of his meeting with the USA president, someone he acknowledged "makes decisions that surprise people sometimes". Trudeau will hold a press conference on his own after he meets with Trump.
The latest round of NAFTA talks kicked off with a discussion of government procurement, already a thorny subject - USA negotiators suggested during the last round in Ottawa that they want to limit Canadian and Mexican access to US projects. The Canadian prime minister is scheduled to visit Mexico on Thursday.
Freeland, a former trade minister appointed to her role this year primarily to deal with Nafta talks, has begun to issue warnings and temper expectations, saying in a television interview this weekend the Trump administration is the most protectionist since the 1930s. U.S. Trade Representative Robert Lighthizer, Freeland and Mexican Economy Minister Ildefonso Guajardo are now expected to meet on October 17 to wrap up the latest round, according to officials familiar with plans who spoke on condition of anonymity.
"What we'd like to do with Nafta is modernize it".
But he also asked for more access to Canada's dairy market. Last week, Washington imposed hefty duties on Canadian-owned Bombadier airplane imports; the levies have made it virtually impossible for the firm to sell its planes in the United States market.
President Donald Trump is welcoming Canadian Prime Minister Justin Trudeau for talks expected to focus on trade and aviation. "We support him in that".
Or perhaps separate bilateral deals with Canada and Mexico will be the way forward, the president suggested.
Trudeau wrapped up his visit to Washington on Wednesday by saying that he continues to believe that renegotiating and renewing NAFTA is the best option for all three countries.