TORONTO -- China accused two detained Canadians on Monday of acting together to steal state secrets, just days after Canada announced it will proceed with a U.S. extradition request for a senior Chinese tech executive.

China arrested the two Canadians on Dec. 10 in what was widely seen as an attempt to pressure Canada to release Meng Wanzhou, the chief financial officer of Chinese tech giant Huawei Technologies, who was arrested in Vancouver on Dec. 1 at the request of U.S. authorities.

Meng's arrest set off a diplomatic furor and has severely strained Canadian relations with China.

The U.S. is seeking the extradiction of Meng, who is also the daughter of Huawei's founder, to face charges she misled banks about the company's business with Iran.

China's official Xinhua News Agency cited unidentified Chinese authorities as saying former Canadian diplomat Michael Kovrig violated Chinese laws by acting as a spy and stealing state secrets and intelligence with the help of Canadian businessman Michael Spavor. It was the first time the two men's cases have been linked.

It said Kovrig often entered China using an ordinary passport and business visas, and acquired information from Spavor, his "main contact."

"Authorities stressed that China is a country ruled by law and will firmly crack down on criminal acts that severely undermine national security," Xinhua said.

The same information was posted on the official news blog of the ruling Communist Party's Central Political and Legal Affairs Commission.

No other details were given and Xinhua said further judicial proceedings would "take place based on the case's progress."

"We are obviously very concerned by this position that China has taken," Canadian Prime Minister Justin Trudeau said. "It is unfortunate that China continues to move forward on these arbitrary detentions."

Kovrig is a former diplomat who was working as an expert on Asia for the International Crisis Group think-tank . Spavor is an entrepreneur known for contacts with high-ranking North Korean officials, including leader Kim Jong Un.

"We are aware of the Xinhua report of 4 March but have heard nothing official about any charges being laid against our colleague, Michael Kovrig," said Hugh Pope, a spokesman for the International Crisis Group.

"Michael's work for Crisis Group has been entirely transparent and in the open as all who follow his work can attest. Vague and unsubstantiated accusations against him are unwarranted and unfair."

After Meng's arrest, a Chinese court also sentenced a Canadian to death in a sudden retrial, overturning a 15-year prison term handed down earlier. Kovrig and Spavor haven't had access to a lawyer or to their families since being arrested.

Canada said Friday that it will allow court hearings for the U.S. extradition request for Meng to proceed.

David Mulroney, a former Canadian ambassador to China, said the new allegations against Kovrig and Spavor are a response to that action.

"Every step in the process will be matched by a step by China. The desire is to raise the raise the pressure to extent that we simply give in," Mulroney said.

Meng is due in court on Wednesday to set a date for the extradition proceedings to start. It could be several months or even years before her case is resolved

Guy Saint-Jacques, also a former Canadian ambassador to China, said Beijing is clearly putting additional pressure on Canada.

"It's a predicable escalation in the crisis," he said. "They are probably hoping it will convince the prime minister to free Meng."

Lawyers for Meng, who is staying at a property she owns in Vancouver after her release on bail, said Sunday she is suing the Canadian government, its border agency and the national police force, alleging she was detained, searched and interrogated before she was told she was under arrest.

Meng's lawsuit alleges that instead of immediately arresting her, they interrogated her "under the guise of a routine customs" examination and used the opportunity to "compel her to provide evidence and information."

Also Monday, Chinese Foreign Ministry spokesman Lu Kang accused Canada and the U.S. of abusing their bilateral extradition treaty. He reiterated Beijing's demand that Washington withdraw its accusations against Meng.

The U.S. has been lobbying its allies to shun Huawei's products on national security grounds, saying Chinese law requires the company to provide the government with intelligence on its foreign clients whenever requested.

A Chinese government spokesman took issue Monday with the U.S. claims that Huawei poses a threat to other countries' information security.

Spokesman Zhang Yesui said U.S. officials were taking China's national security law out of context and "playing up the so-called security risks" associated with Chinese companies.

The 2017 law borrows from other countries' experiences and is designed explicitly to "protect human rights and the lawful rights of individuals and organizations," he said.

"This kind of behaviour is interference into economic activities by political means and is against World Trade Organization rules. It disrupts an international market order that is built on fair competition," Zhang told reporters. "This is a typical case of double standards that is neither fair nor ethical."

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Christopher Bodeen contributed to this report from Beijing.