STORY: 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."
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.