Though the USA president often threatens to withdraw from NAFTA, the latest pledges are piling up pressure on negotiators who are trying to wrap up more than a year's worth of talks and strike a deal that could be signed before December 1.
The letter detailed Canadian trade practices that "may violate Canada's existing trade commitments to the United States by effectively discouraging US dairy exports to Canada" and stressed that "districts and states rely on the jobs the dairy industry provides and can not afford further protectionist policies from our northern neighbor".
"We're not saying we don't want to move swiftly to try and get a deal".
Dan Ujczo, an Ohio-based trade lawyer with Dickinson Wright, said while getting rid of the cultural exemption seems to fit with Lighthizer's philosophy, he can't see Trump holding up an otherwise good deal because of it.
Trump almost tore up the NAFTA pact previous year after visiting farmers in Wisconsin, a major USA producer of dairy products that Washington says has been hurt by Canadian protectionism.
He warned Congress on Wednesday not to "interfere" with the negotiations and said he would "simply terminate NAFTA entirely and we will be far better off".
"There is good faith and good will on both sides".
Foreign Affairs Minister Chrystia Freeland is to resume talks with US trade czar Robert Lighthizer, whom she has praised as a "good faith" negotiator in the face of President Donald Trump's Twitter barrages.
National Post: "From cars to medicine, uncertainty of NAFTA deal means consumers lose out, experts say" - "Under nearly any normal circumstance, the negotiation of a trade pact between countries should result in benefits for consumers, say experts who are closely watching the North American free trade talks unfold in Washington".
Trump's actions 'detrimental' to country's health, says anonymous official
FILE - White House press secretary Sarah Sanders speaks during a press briefing at the White House, May 7, 2018. In an official written statement, the White House also attacked the opinion column and criticized its author.
U.S. President Donald Trump has threatened to push ahead with a bilateral deal with Mexico, effectively killing the nearly 25-year-old three-country pact, which covers $1.2 trillion in trade. On Friday, Trump was quoted as saying in an interview with Bloomberg News that any deal with Canada would be "totally on our terms".
Trudeau said on Tuesday: "There are a number of things we absolutely must see in a renegotiated NAFTA", and reiterated he would not sign a bad deal.
Some US labor advocates who embraced Trump's longtime characterization of NAFTA as "the worst trade deal ever" are lauding the president for championing US workers in the NAFTA rewrite. Free Trade Agreement signed in 1987.
"It's weird that Canada would be re-stating this so publicly as a red line at this point ... because it's not something that has figured prominently in American discussions over trade priorities", said Mark Warner, a Canada-U.S. trade expert based in Toronto. A lot is riding on a new NAFTA deal.
Foreign companies seeking relief through Canada's Federal Court of Appeal are often repeatedly coming up empty handed, said Todgham Cherniak, a former federal tax court adviser.
But other issues have yet to be worked out, including Canada's cultural exemption in NAFTA.
Veuger also notes that Canada is deepening its trade relationship with Beijing in part by expanding its oil and gas exports to China.
"You have to be careful about what he says and what he's actually doing". They were rushing to bridge their differences by the end of August so Canada could join a preliminary pact the US had struck with Mexico just days earlier.