Donald Trump’s initial public reaction to Ontario’s anti-tariffs TV ad gave absolutely no indication that it had triggered him so much that he would later kick the legs out from under the negotiating table.

The U.S. president first saw the ad on Monday night, three whole days before he abruptly announced in a social media post that he was terminating trade talks with Canada .

Speaking at the White House on Tuesday, Trump depicted the ad as evidence that his tariffs are making America rich again and dismissed it as unlikely to have any impact on its intended audience.

“I even see foreign countries — now that we are doing very well with [tariffs] — taking ads [that say], ‘Don’t go with tariffs!'” Trump told an audience of Republicans.

“I saw an ad last night from Canada,” he continued, adding, “But I do believe that everybody’s too smart for that.”

Trump then shifted to other topics and went for another 30 minutes without mentioning the ad again. He didn’t once complain about its use of Ronald Reagan’s words to send an anti-tariff message to Americans.

WATCH | ‘It’s not just about one ad,’ says Trump economic adviser:

Canadians have been ‘very difficult’ to negotiate with on trade, Trump adviser says

It’s all prompting questions about whether the ad is the real reason behind Trump’s move or if that was merely a pretext to put negotiating pressure on Canada.

One of Trump’s top advisers says the ad is only part of the story.

Canada ‘very difficult to negotiate with’

Kevin Hassett, the director of Trump’s National Economic Council, told reporters at the White House on Friday that Trump’s post cancelling the talks “reveals his frustration with the actions and postures of the Canadians through months of negotiations.”

“The Canadians have been very difficult to negotiate with,” he said.

“You look at all the countries around the world that we’ve made deals with, and the fact that we’re now negotiating with Mexico separately, reveals that it’s not just about one ad, that there’s frustration that’s built up,” he added.

What remains unclear is what exactly about the negotiations with Canada has been so frustrating to Trump.

Barely two weeks ago, after what was widely reported to be a cordial meeting at the White House with Prime Minister Mark Carney, Trump directed his two top trade officials, Commerce Secretary Howard Lutnick and U.S. Trade Representative Jamieson Greer, to sit down with the Canadians and try to reach quick deals in relation to steel, aluminum and energy.

The talks began immediately in Washington and plugged along through mid-October. There was even a report in the Globe and Mail this week that a deal was close enough that it could be ready for Carney and Trump to sign at the APEC summit at the end of this month.

As recently as Wednesday evening, a spokesperson for Canada-U.S. Trade Minister Dominic LeBlanc told CBC News that progress was being made.

Roughly 24 hours later, Trump slammed the Ontario ad as “FAKE” and announced “ALL TRADE NEGOTIATIONS WITH CANADA ARE HEREBY TERMINATED.”

There are plenty of Canadian observers who think the ad is not the president’s real concern.

“Trump’s decision has nothing to do with the entirely justified advertising campaign of [Ontario] Premier [Doug] Ford,” wrote Dimitri Soudas, who served as communications director for former prime minister Stephen Harper, in a post on X.

“Don’t let yourself be fooled,” Soudas said. “Trump wants concessions that no Canadian premier should ever accept. Trump wants to completely annihilate the Canadian automotive sector.”

Lana Payne, national president of Unifor, the largest private sector union in Canada, said Trump wants to bully Canada into economic subservience.

“The president’s fake outrage over a TV ad is just his latest ploy to sabotage any progress made by the Canadian negotiating team,” Payne said in a statement on Friday.

So what are the real frustrations?

On Thursday — mere hours before Trump cancelled the talks — Ottawa hit General Motors and Stellantis with tariffs in retaliation for reducing vehicle production in Canada.

Brian Clow, who advised former prime minister Justin Trudeau on Canada-U.S. trade, says that move clearly irked the Trump administration.

“The ad is a problem in that it has caused the president to do what he did, break off the talks. But this is more than about just one single ad,” Clow told CBC News on Friday.

Citing a source close to both the Canadian and U.S. governments, the Globe and Mail reported Friday that Canada’s position on Israeli Prime Minister Benjamin Netanyahu and its consideration of China as a strategic partner also factored into Trump’s move

In his social media posts slamming the Ontario ad, Trump drops a not-so-subtle hint of his own about something else that’s really on his mind.

“Canada is trying to illegally influence the United States Supreme Court in one of the most important rulings in the history of our Country,” Trump said in a Friday morning post about the ad.

WATCH | Ontario’s one-minute ad that uses Ronald Reagan’s anti-tariff message:

See the anti-tariff ad Doug Ford has been airing in the U.S.

He claimed the ad was designed to “interfere” with what he called “THE MOST IMPORTANT CASE EVER.”

While the idea that Supreme Court justices would somehow be swayed by a TV ad borders on preposterous, the case is indeed important.

It is the administration’s request to get the Supreme Court to overturn a ruling by the U.S. Federal Court of Appeals that the president’s move to impose broad-based tariffs on Canada, Mexico and dozens of other countries was unconstitutional.

The Supreme Court is scheduled to hear arguments in November. If Trump loses, the tariffs he slapped on Canada and Mexico over fentanyl trafficking and illegal immigration would be quashed, along with what he likes to call his “Liberation Day” tariffs.

The case, however, has no impact on Trump’s ability to impose the sectoral tariffs on steel and aluminum, currently at 50 per cent, which is what the negotiations with Canada that he just terminated were focused on.

Carney didn’t even mention the ad controversy when he spoke to reporters Friday morning before flying to Asia on a trip that will likely bring him face-to-face with Trump.

“A lot of progress has been made, and we stand ready to pick up on that progress and build on that progress when the Americans are ready to have those discussions,” Carney said.

Ford’s provincial government will pull the ads from U.S. screens after this weekend. What remains to be seen is whether that’s really all Trump wanted to send his team back to the table with Canada.