Ontario Premier Doug Ford has demanded an apology from the US ambassador to Canada following a tense exchange between the envoy and the province's trade representative.

The exchange - described by CBC News as “an expletive-laced tirade” - was between US envoy Pete Hoekstra and Ontario trade representative David Paterson over a TV advert criticising Trump's tariffs.

Calling the remarks "absolutely unacceptable" and "unbecoming of an ambassador", Ford urged Hoekstra to make amends. "Pete, you gotta call Dave up and apologise. It's simple," Ford said.

Last week, President Trump suspended trade talks with Canada over the advert and threatened to impose an additional 10% tariff on Canadian imports.

"You know, the cheese slipped off the cracker. I get it,” Ford said at a press conference on Wednesday, referring to Hoekstra's outburst. “You're ticked off, but call the guy up because you're a good guy, and Dave's my champion."