Canada moved away from diplomatic caution on Friday and made is first formal demand for China to immediately release two Canadians who have been detained in apparent retaliation for Canada's arrest of a top Chinese tech executive.

The U.S., the U.K. and the EU also issued statements in support of Canada.

"We are deeply concerned by the arbitrary detention by Chinese authorities of two Canadians earlier this month and call for their immediate release," Canadian Foreign Minister Chrystia Freeland said.

A senior government official said China's ambassador to Canada was called on Friday and told of Canada's demand. The official spoke on condition of anonymity because of lack of authorization to discuss the call publicly.

Meng Wanzhou, chief financial officer of Chinese telecommunications giant Huawei, was arrested in Canada on Dec. 1 at the request of the United States, which wants her extradited to face charges that she and her company misled banks about the company's business dealings in Iran.

Nine days later, the Chinese detained Canadian ex-diplomat Michael Kovrig and Canadian entrepreneur Michael Spavor on vague allegations of "engaging in activities that endanger the national security" of China.

Freeland's declaration marked a harder tone from Canadian officials. Prime Minister Justin Trudeau had been criticized by the opposition for what they called unacceptable reticence over his suggestion Wednesday that raising demands for their release would be akin to "to stomping on the table" without achieving their release.

Freeland said that that Canada is honoring its extradition treaty with the United States and said it's conducting a fair and transparent legal proceeding with respect to Meng.

U.S. State Department spokesman Robert Palladino also reiterated that Canada is honoring its extradition treaty commitments.

"We also express our deep concern for the Chinese Government's detention of two Canadians earlier this month and call for their immediate release," Palladino said. U.S. Secretary of State Mike Pompeo also called for their release last week.

U.K. Foreign Secretary Jeremy Hunt said in a statement the U.K. is confident that Canada is respecting its extradition treaty with the U.S. and said he is "deeply concerned" that China may have detained the two Canadians for political reasons.

The EU, meanwhile, issued a statement saying, "The declared motive for the arrest and detention of Michael Kovrig and Michael Spavor, both Canadian nationals, raises concerns about legitimate research and business practices in China."

The show of support from allies is significant for Canada, which has felt relatively isolated in recent months, particularly following U.S. President Donald Trump's criticism of Trudeau and his lack of public support.

In August, Saudi Arabia expelled Canada's ambassador to the kingdom and withdrew its own ambassador after Canada's foreign ministry tweeted support for an arrested Saudi activist. The Saudis also sold Canadian investments and ordered their citizens studying in Canada to leave.

No country, including the U.S., spoke out publicly in support of Canada, and the Trump administration has been steadfast in its support for Saudi Arabia.