An urgent phone call from Justin Trudeau to Donald Trump helped defuse the president's latest threat to scrap the North American Free Trade Agreement — even though it's doubtful Canada and Mexico were the targets of this latest trade flare-up.

That's the view of senior officials advising the prime minister, who spoke to CBC News on condition of anonymity because they weren't authorized to speak publicly on the matter.

The officials said they believe the real target of Trump's threat to scrap NAFTA was the U.S. Congress.

With the 100 days in office mark fast approaching, Trump has struggled to make progress on key election promises on health care or tax reform.

Two senior government officials told CBC News they believe the renewed threat of scuttling NAFTA was actually designed to unsettle U.S. legislators whose states rely on cross-border trade in an attempt to force their co-operation on other issues.

Trump 'was open to listening'

During their Wednesday phone call — the second conversation this week — Trudeau told Trump he understood his frustration with Congress, according to one senior government official. Trudeau even expressed relief that Canada didn't share the U.S. system of government. But the prime minister cautioned the president that acting on that frustration by cancelling NAFTA would hurt a lot of regular people.

"It would cost a lot of jobs, create lots of uncertainty and make future negotiations very difficult," is how the official described the prime minister's message to the president.

"It was a very good call," the official said. "(Trump) was open to listening. Which is good."

Won't derail charm offensive

The PMO felt its efforts to deal with Trump on contentious trade issues had been going very well — until this week and last, when the president launched a broadside at Canada's dairy sector, imposed duties on softwood lumber and then floated the threat that he was poised to withdraw from NAFTA.

Trudeau says he convinced Trump not to cancel NAFTA1:37

Canadian government officials say those cases won't derail their charm-and-diplomacy approach of dealing with the U.S. administration.

Senior federal ministers will continue to meet with their counterparts in the U.S. and highlight the economic value of the Canada-U.S. trading relationship in speeches and in visits to key economic states.

But, the officials said, tough public stances by premiers and mayors are welcome and, in fact, are seen as helping strengthen Ottawa's hand. They point to B.C. Premier Christy Clark's demand that Ottawa ban the shipment of all thermal coal — including U.S. thermal coal — through British Columbia in retaliation for softwood lumber duties.

The officials said threats like that underscore the interconnectedness of the two economies and illustrate to the president how a trade war can spiral out of control. By targeting coal, Clark's call for retaliation also hits one of Trump's core constituencies.

The officials said Clark's move also allows Trudeau to continue his diplomatic approach with Trump while pointing to internal domestic pressures as a sign that the goodwill can't last forever, as a way to make the case for co-operation.

U.S. cable news part of plan

Trudeau will seek to speak directly to Trump whenever the trade discussions escalate to that level.

But the officials said the government will also try to send message to the president through the medium they know he loves: cable news.

Trump is known to be a voracious consumer of TV news. The officials said there will be a push to keep get senior Liberal cabinet ministers on U.S. cable television, with a specific goal of getting Chrystia Freeland on what is seen as Trump's favourite channel — Fox News.

Trump decided to not cancel NAFTA after talking to Canada/Mexico1:29