But he is not saying whether he has received specific assurances that the conversation happened.
In a press conference on Tuesday, Trudeau was asked by reporters what assurances he has received that Trump pressed Chinese President Xi Jinping in Japan over the weekend on the detentions of Michael Kovrig and Michael Spavor, as he had said he would do last week.
Both were arrested in December 2018 in retaliation for the detention of Huawei CFO Meng Wanzhou by Canadian border agents at the behest of the U.S.
“Have you been given any assurances that President Trump raised the issue of the detained Canadians in his conversation with the Chinese as he publicly said he would?” the reporter asked.
“I am confident that the Americans brought up the issue and President Trump brought up the issue of the detained Canadians in China,” Trudeau said. “As you know, this is an issue we take extremely seriously.”
WATCH: Trump willing to raise Canada’s concerns to Chinese president
His remarks remain largely unchanged since the weekend when he was at the G20 Summit in Osaka, Japan, and Trudeau did not provide any clarification on what makes him so confident that the issue was raised when American officials are refusing to confirm whether the promised was fulfilled.
Global News has made repeated inquiries to the White House about whether that conversation took place but has not yet received a response.
The U.S. Department of Justice charged Meng and Huawei with 23 counts of evading American sanctions on Iran and corporate espionage in January, one month after Canadian officials detained her following an American request.
She is currently fighting extradition to the U.S. in a Vancouver court.
WATCH: China says ‘Canada is to blame’ for problems in relationship
Just days after her detention, China arrested Kovrig and Spavor and has since charged them with unspecified claims of endangering national security, prompting dozens of Canadian allies to speak out against the decision, which Trudeau bills as arbitrary.
Canadian officials have been working on a concerted campaign to get allies to apply pressure to China for their release, and that effort has yielded a number of high-profile remarks by top Trump allies in the U.S., including his national security adviser John Bolton, condemning the Chinese.
Trump promised to raise the detentions directly with Xi last week, saying that, at Trudeau’s request, “I will absolutely bring that up.”
He also pledged: “Anything I can do to help Canada, I will be doing.”
Trudeau stressed both over the weekend and on Tuesday that he raised the issue himself — repeatedly — with Xi during their talks.
But it’s not clear why both the Canadians and Americans are saying little about the specifics of whether Trump did the same.
The question also comes after Trump announced a trade war cease-fire with China over the weekend, keeping U.S. tariffs in place while freezing Chinese ones from going into effect as the two sides resume negotiations over trade.