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."

The advert, which was paid for by the Ontario government, uses a quote from Reagan saying tariffs “hurt every America”, taking excerpts from the former president’s 1987 national radio address focused on foreign trade.

Ford wanted to use the advert to sway public opinion on tariffs in conservative, Trump-backed, areas. The premier has said the ad had “over one billion impressions” and been seen by a global audience.

“What do they expect me to do? Sit back and roll over like every other person in the world,” he said.

The spot also aired during the first two World Series games between the Toronto Blue Jays and the Los Angeles Dodgers, which Ford hailed as "the most successful ad in North American history".

“They’re talking about it in the US, and they weren’t talking about it before I put the ad on,” Ford said.

But it has frustrated many in the Trump administration, especially President Donald Trump who threatened to hike tariffs on Canada 10% “over and above” current levies in the wake of Ford’s action.

When Trump was asked to expand on what the additional tariffs would look like he said, “I don’t know when it’s going to kick in, and we’ll see, but I don’t really want to discuss it”.

There is currently a 35% tariff on Canadian goods, though most are exempt under an existing free trade agreement. Certain sectors, however, have separate tariffs, including 50% on steel and aluminium and 25% on automobiles.

On Wednesday, the US senate voted to approve a resolution that would block Trump’s tariffs on Canada.

The 50-46 vote would terminate the national emergency used to impose tariffs on some goods from Canada.

But the measure is unlikely to get the support needed in the US House of Representatives.