Law-enforcement authorities in the United States confirmed on Tuesday that they will formally seek the extradition from Canada of Huawei chief financial officer Meng Wanzhou to face bank-fraud charges.

The next step in Meng’s case will further test already strained ties between Canada and China, as Prime Minister Justin Trudeau’s government faces pressure from Beijing to intervene in a judicial process that is seen by some as being politically motivated.

The Chinese Embassy in Canada has said that the law-enforcement action is “political persecution against Chinese enterprise and [a] Chinese citizen.”Some legal analysts have also argued that the action is an overreach by US authorities and a breach of long-adhered-to international norms.

US President Donald Trump has suggested that Meng could be used as leverage in trade negotiations, saying that he would potentially be willing to intervene to have the case dropped in exchange for a trade deal.

But China’s response to the US legal action, which has targeted Canadian citizens, has also successfully turned much of the attention in Canada away from scrutiny of the US legal action and Ottawa’s participation to China’s lack of due process or transparency.

After Meng’s apprehension, the news of which came to light in early December, Chinese authorities promptly detained two Canadian nationals living in China. Former diplomat Michael Kovrig and businessman Michael Spavor are currently being detained under suspicion of engaging in “activities that endanger China’s national security.”

In a separate case, a Canadian citizen who had been sentenced to prison time in China on drug-trafficking charges had his sentence abruptly changed to execution in an expedited and high-profile legal process. International press organizations were invited to the defendant’s appeal hearing, which followed warnings from Chinese diplomats and state media that Canada would face consequences for its handling of Meng’s case.

Trudeau and Canadian Foreign Affairs Minister Chrystia Freeland have touted their efforts to rally support for the detained Canadians, which have included 19 high-level talks with allies.

The prime minister defended Canada’s actions in an address on Monday, insisting that the legal process in Meng’s case was not influenced by political considerations.

“It’s a very clear principle,” he said, as quoted by the Canadian Broadcasting Corporation. “It has served us well as a planet over the past decades, that we have systems of justice that are independent of political interference and Canada wil l always defend that.”

Canadian Ambassador to the US David MacNaughton suggested in an interview published by The Globe and Mail on Monday that China should be directing its ire at the United States.

Washington is “seeking to have the full force of American law brought against [Meng], and yet we are the ones who are paying the price,” MacNaughton lamented.

Chinese Foreign Ministry spokeswoman Hua Chunying spent much of a regular press conference on Monday fielding questions regarding the detained Canadians. The renewed attention on the cases came after 140 former diplomats and academics signed an open letter to President Xi Jinping urging the release of the two.

Hua said the signatories of the letter “are in no position to speak for those who remain committed to promoting normal and friendly exchanges between China and the rest of the world.”

“China is the safest country on Earth. Safety and freedom in China are guaranteed as long as no violations of Chinese laws and regulations are committed. These people are deliberately creating a sense of panic,” she said of the group.