Officials have identified the main sticking points as Canada's dairy quota regime, Ottawa's desire to keep a trade dispute-resolution mechanism and Canadian media laws that favor domestically produced content.
Wiens declined to say what action the organization would take if an updated NAFTA deal gave the US a greater chunk of the Canadian market, but did not rule out campaigning against ratification of the agreement, or the Liberal government.
The in-person, high-level negotiations got back underway as events marking the 17th anniversary of the 2001 attacks took place around the USA, including at the Pentagon with Vice President Mike Pence, not far from where the trade meetings are taking place.
The talks are focused on US demands to scrap the so-called Chapter-19 dispute resolution mechanism in NAFTA, overturn some of Canada's current "carve-out" of cultural industries from free-trade rules and loosen protections under the dairy sector's supply management system.
With so much uncertainty, Freeland and Prime Minister Justin Trudeau have regularly been dogged by questions about the fate of NAFTA.
A late day comment from Pres. Trump boosted the precious metal and the Canadian dollar where he said "Trade talks going well".
Trump has raised pressure on Ottawa, threatening to impose duties on Canadian auto imports, which Trudeau said would be "devastating" for the Canadian auto sector.
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But with Apple boosting the average iPhone selling price by almost 20 percent, it still meant a bumper year for the tech firm. Instead of using stainless steel like the iPhone X and XS, the XR uses 7000 series aluminium for its metal frame.
Trudeau, facing elections in 2019, said on Sunday (June 10) that Canada "will not be pushed around", triggering a fierce attack from Trump and his advisers, on Tuesday (June 12). "I think there will be agreement on NAFTA based on the benefit to all three national economies".
"Without Chapter 19, NAFTA is utterly useless as it would subject Canada and Mexico to the vagaries of the USA political system and its courts when determining trade policy actions", said Derek Holt, vice-president at Scotiabank Economics, in a note recently.
He said, however, it was wrong for Canada to have publicly declared it would not accept concessions on certain files.
"Even if we gave him everything he wanted - and there is no way we would ever do that - who can say whether he'd be satisfied?" said one source, who declined to be identified given the extreme sensitivity of the situation.
Canada's Chrystia Freeland said of the negotiations that: "It's going to take flexibility on all sides".
Freeland and Lighthizer left the bargaining table Friday without a deal following two weeks of negotiations. He said Canada and the United States spent a lot of time last week reconciling what the US and Mexico had already agreed upon. Eares are on the ground for USA and China developments but at the fore again was the NAFTA negotiations. "It would be a good modernized deal if Canada is brought into it". "That's not who we are", Craft said in prepared remarks. Canadian officials had said previously that they are working on the assumption that they have until the end of September to make a deal.