China warns 'naive' Canada not to count on the US

China on Wednesday warned Canada not to be "naive" and believe that US pressure could help resolve thorny issues plaguing relations between Ottawa and Beijing.

Prime Minister Justin Trudeau said Tuesday he was "confident" US President Donald Trump had brought up the cases of Canadians detained in China during weekend talks with President Xi Jinping at the G20 in Japan.

"Don't be naive and mistakenly think that mustering a certain so-called ally to put pressure on China will have an impact," Chinese foreign ministry spokesman Geng Shuang said at a regular press briefing.

Ottawa "should not naively think its so-called ally will really exert itself on Canada's behalf", he said.

"At most the (Americans) will move their lips a bit, because in reality this is an issue between China and Canada," Geng said at a regular press briefing.

Relations deteriorated between China and Canada following the December arrest in Vancouver of Meng Wanzhou, a top executive at Chinese telecom giant Huawei, who is wanted by the United States for allegedly circumventing sanctions on Iran.

In moves widely seen as retaliation, Chinese authorities arrested two Canadians on national security grounds and blocked imports of Canadian agricultural products.

Trudeau said he had spoken to Xi about ex-diplomat Michael Kovrig and consultant Michael Spavor during brief, informal exchanges on the sidelines of the G20 summit last week.

Geng blamed Ottawa for the fraught relations.

"Canada knows clearly what the crux of the issue is between the two countries," he said.

"We hope that Canada will take measures to put China-Canada bilateral relations back on track as soon as possible," Geng said.