Canadian Prime Minister Mark Carney said on Saturday he had apologised to U.S. President Donald Trump over an anti-tariff political advertisement and had told Ontario Premier Doug Ford not to run it.

Carney, speaking to reporters after attending an Asia-Pacific summit in South Korea, said he had made the apology privately to Trump when they both attended a dinner hosted by South Korea's president on Wednesday.

"I did apologise to the president," Carney said, confirming comments by Trump made on Friday.

Carney also confirmed that he had reviewed the ad with Ford before it aired, but said he had opposed using it.

"I told Ford I did not want to go forward with the ad," he said.

The ad, commissioned by Ford, an outspoken Conservative politician who is sometimes compared to Trump, uses a snippet of Republican icon and former President Ronald Reagan saying that tariffs cause trade wars and economic disaster.

In response, Trump announced that he was increasing tariffs on goods from Canada, and Washington has also halted trade talks with Canada.

When departing South Korea earlier this week, Trump remarked he had a "very nice" conversation with Carney at that dinner, but did not elaborate. On Friday Trump still said the United States and Canada will not restart trade talks.

Carney said his talks with Chinese President Xi Jinping on Friday were a turning point in relations after years of tensions.

The last formal meeting between the leaders of Canada and China happened in 2017 when then-Prime Minister Justin Trudeau had a brief exchange with Xi at a meeting in San Francisco.

In recent years, Canadian citizens were detained and executed in China, and Canada's security authorities concluded that China interfered in at least two federal elections.

Carney said he had discussed foreign interference with Xi, among other issues.

The trip to Asia had been part of efforts to reduce Canada's reliance on the United States, Carney said.

"It can't happen overnight, but we're moving very fast," he said.