In December, Meng Wanzhou, the 46-year-old CFO of Chinese telecom giant Huawei, was arrested in Canada by request of American officials who say she violated sanctions against Iran using a subsidiary of Huawei. According to CBC News, U.S. officials have indicated to David MacNaughton, Canadian ambassador to the United States, that they will be filing a formal request needed to extradite Wanzhou.

The case has created tension between Canada and China, which has culminated in Chinese Foreign Ministry spokesperson Hua Chunying declaring that both the U.S. and Canada have abused the extradition process in the case of the Chinese CFO. Chunying also said that “China will, of course, respond to U.S. action.” However, the spokesperson did not go into any further details.

The United States did not back down in the face of this threat. In an email, Department of Justice spokesperson Marc Raimondi told CBC News, “We will continue to pursue the extradition of defendant Ms. Meng Wanzhou, and will meet all deadlines set by the US/Canada Extradition Treaty.” In addition, Canada’s Foreign Affairs Minister told reporters Tuesday after the Davos economic summit in Switzerland, “The Canadian legal system is fair and impartial to everyone .. the detention of Ms. Meng is not about a Canadian case against her. She is neither charged or convicted of anything in Canada. We have an extradition treaty with the U.S., we share with the U.S. the largest demilitarized border and Canada is a rule-of-law country and we act and honour our international treaty commitments.”

Now, China appears to have retaliated against Canada by holding Canadian citizens Michael Kovrig and Michael Spavor as detainees, claiming that the men were “engaging in activities endangering national security.” Canada’s ambassador to China, John McCallum says that the men endure up to 4 hours of interrogation daily with no access to lawyers.

Canada’s Prime Minister Justin Trudeau is not pleased with these developments, and mentioned to CBC News the case of another Canadian, Robert Schellenberg, who faces the death penalty in China after a retrial of a drug smuggling case. “It is of extreme concern to us as a government, as it should be to all our international friends and allies, that China has chosen to begin to arbitrarily apply [the] death penalty… as in this case facing a Canadian,” Trudeau said.