The People's Procuratorate of Beijing Municipality filed a prosecution against Kovrig on Friday for "for spying on state secrets and intelligence".
Former diplomat Michael Kovrig and businessman Michael Spavor were arrested in late 2018 on state security charges, soon after Canadian authorities arrested Huawei Technologies Co's chief financial officer, Meng Wanzhou, in Vancouver on a USA warrant.
Last month, Ms Meng lost a legal bid to avoid extradition to the United States to face bank fraud charges, dashing hopes for an end to her house arrest in Vancouver. Kovrig's case is being handled by prosecutors in Beijing, and Spavor's in the northeastern province of Liaoning.
Late last month, a BC Supreme Court judge ruled that Wanzhou must stay in Canada and keep fighting the United States extradition order.
Speaking to the media, Trudeau said he is continuing to work with the Chinese government to send the "two Michaels home".
Zhao denied any link between the cases of the Canadians and that of Meng, saying China is a country under the rule of law.
Chinese authorities have brought espionage charges against two Canadian citizens detained after Huawei's CFO was arrested by Ottawa.
The next round of legal arguments is set to focus on whether Meng's arrest was unlawful and whether the US records of the case contain misstatements or omissions. Meng, who is also the daughter of the Chinese mobile giant's founder, was taken into custody by the Royal Canadian Mounted Police at Vancouver International Airport as she was traveling from Mexico to Hong Kong.
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Meng is out on bail as hearings are ongoing in B.C. Supreme Court after a judge rejected the first set of arguments from her lawyers late last month in a bid to set her free.
The Chinese embassy in Ottawa denounced that decision by Associate Chief Justice Heather Holmes and called once more for Meng's immediate release.
Canadian foreign minister Francois-Philippe Champagne said that after the May ruling on Meng, Canada would "continue to pursue principled engagement with China to address our bilateral differences".
"Each passing day is a stain on China's reputation, an injustice to Michael and act of cruelty to his family and loved ones", Crisis Group said in a tweet on Friday morning, marking his 557th day in detention.
In contrast, the trial of Kovrig and Spavor would likely happen fairly quickly, experts said.
The cases have been closely linked with the USA push to extradite Huawei executive Meng Wangzhou from Canada.
China has also blocked billions in Candian agricultural exports, including suspending imports of Canadian canola oil.
Earlier this month, Huawei's ambitions to be a player in Canada's 5G network were very much cast in doubt after two of the country's three largest telecom companies announced partnerships with the Chinese company's European rivals.
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Texas officially made it a holiday in 1980, and 45 more states and the District of Columbia have since followed suit. Like Juneteenth, the 30th of May was a daylong celebration of fun, barbecue, snow cones and hot dogs.