Chinese President Xi Jinping on Wednesday criticised Canadian Prime Minister Justin Trudeau in person over alleged leaks of their closed-door meeting at the G20 summit, a rare public display of annoyance by the Chinese leader.

In video footage published by Canadian broadcasters, Xi and Trudeau can be seen standing close to each other and conversing via a translator at the summit on the Indonesian island of Bali.

"That is not appropriate, and we didn't do it that way," Xi said in Mandarin, smiling.

"If there is sincerity, we can communicate well with mutual respect, otherwise the outcome will not be easy to tell."

His displeasure was likely a reference to media reports that Trudeau brought up "serious concerns" about alleged espionage and Chinese "interference" in Canadian elections when meeting with Xi on Tuesday, his first talks with the Chinese leader in more than three years.

A translator for Xi can be heard in the video telling Trudeau that "everything we discussed was leaked to the paper(s), that's not appropriate."

The video captured a rare candid moment for Xi, whose image is carefully curated by Chinese state media.

Trudeau responds to Xi's initial criticism by saying, "In Canada we believe in free and open and frank dialogue and that is what we will continue to have, we will continue to look to work constructively together but there will be things we disagree on."

Before he finished speaking, however, Xi, looking slightly exasperated, cuts him off and says, "Create the conditions, create the conditions, OK?" before smiling, shaking Trudeau's hand and walking off.

Neither the Chinese foreign ministry nor state media have published anything on talks between Xi and Trudeau. The two held a 10-minute informal meeting on the sidelines of the G20 summit on Tuesday, according to a government source. Xi has held nine formal bilateral meetings with other heads of state while at the summit, according to the Chinese foreign ministry website.

Canada never released an official readout from the meeting, but Trudeau did confirm the conversation and the points that he made to Xi at a news conference at the end of the G20.

"Canada trusts its citizens with information about the conversations that we have in their name as a government," Trudeau said according to a transcript of the news conference.

Trudeau added not all conversations with leaders were going to be easy, but pointed out that "systems" in the two countries are different and in China "there is not always the same openness that a democratic leader can and must have with his citizens."

The short but revealing Xi-Trudeau exchange highlighted tensions between China and Canada, running high since the detention of China's Huawei Technologies executive Meng Wanzhou in 2018 and Beijing's subsequent arrest of two Canadians on spying charges. All three were later released.

Despite the release, tensions have recently resurged.

An employee at Canada's largest electricity producer Hydro-Quebec who was involved in researching battery materials has been charged with espionage for allegedly trying to steal trade secrets to benefit China, Canadian police said on Monday.

News of the arrest came as Trudeau and Xi were attending the G20 summit.

This month, Canada ordered three Chinese companies to divest their investments in Canadian critical minerals, citing national security. (Reuters)