An offhand comment by Canada's ambassador to the United States about Cuba touched off a minor diplomatic flap between the federal government and the U.S. State Department, CBC News has learned.

About two months ago, officials in the Trump administration reached out to the Prime Minister's Office to float the idea of U.S. Vice President Mike Pence coming to Ottawa to lobby for the swift passage of the revised NAFTA trade agreement, dubbed the USMCA by the White House.

Multiple federal government sources spoke to CBC News anonymously about what happened next.

As the Trump administration was making arrangements for Pence's visit, controversial steel and aluminum tariffs imposed by U.S. President Donald Trump were still being enforced against Canadian products — a major source of tension between the two countries.

Tariff tensions

The sources said it was Canada's position that the Americans did not recognize the depth of anger in Canada over the tariffs — especially since President Trump had used a national security provision to implement them.

The sources said Ottawa worried that a visit by Pence with the tariffs still in place would be "difficult" or, at best, "frosty." One senior source said there were fears of a repeat of the diplomatic disaster that ended the G7 Summit in Charlevoix, Quebec last summer.



So when Canadian Ambassador to the United States David MacNaughton called U.S. Ambassador to Canada Kelly Craft shortly after Pence's visit was proposed — to learn more about what the Americans had in mind — he did not shy away from sharing Canada's concerns.



Sources say MacNaughton told Craft that Pence likely would get a warmer reception in Cuba — since Cubans at least understand that they're viewed as a national security threat by Washington.

Kid gloves

That comment was a departure from the Trudeau government's strategy of treating the White House with kid gloves and carefully avoiding confrontation with a temperamental president. Prime Minister Justin Trudeau has been careful not to say anything publicly that could upset Trump, given the importance of the Canada-U.S. trading relationship.



When the message was passed from Ambassador Craft to members of the Trump administration, it didn't go over well.



Sources say it wasn't long before Foreign Affairs Minister Chrystia Freeland's office received a request for an "urgent" phone conversation from the office of U.S. Secretary of State Mike Pompeo.



Freeland's office was not aware of MacNaughton's specific comment, nor did it have any idea of what Pompeo wanted to talk about.

Foreign Affairs Minister Chrystia Freeland shakes hands with Secretary of State Mike Pompeo during a photo opportunity before their meeting at the State Department, Friday, May 11, 2018 in Washington. (Alex Brandon/The Associated Press)



Staff in Freeland's office frantically pulled up files on multiple topics — so that she could quickly pivot to discuss whatever was on Pompeo's mind.



When Pompeo demanded an explanation for MacNaughton's comment about Cuba, sources said, Freeland's voice dropped to a low, reassuring tone as she tried to smooth over any tensions.



She repeatedly told Pompeo that Pence would be welcome in Canada at any time. Planning for the visit continued.



All of the sources that spoke to CBC News insist that all the conversations on the topic were professional in tone. Staff in Freeland's office frantically pulled up files on multiple topics — so that she could quickly pivot to discuss whatever was on Pompeo's mind.When Pompeo demanded an explanation for MacNaughton's comment about Cuba, sources said, Freeland's voice dropped to a low, reassuring tone as she tried to smooth over any tensions.She repeatedly told Pompeo that Pence would be welcome in Canada at any time. Planning for the visit continued.All of the sources that spoke to CBC News insist that all the conversations on the topic were professional in tone.

'Blunt beyond belief'

One senior source said that MacNaughton's comment turned out to have a positive effect, since it impressed upon the Trump administration the depth of Canadian outrage over the tariffs.



"Unless you're blunt beyond belief, (the Americans) don't get it."



Ottawa had been trying to get the attention of Trump's people for months as it struggled to negotiate an end to the steel and aluminum tariffs.





It wasn't until American trade talks with the Chinese soured that the Trump administration considered changing its position on Canada.



Tensions eventually eased when the U.S. announced it would lift its tariffs on Canadian and Mexican steel and aluminum on May 17.



Pence eventually visited Trudeau in Ottawa on May 30. The visit went smoothly, by all accounts.