OTTAWA -- The United States is marking the second year of the imprisonment of two Canadians in China by calling for their immediate release.

A statement from the acting American ambassador to Canada, Katherine Brucker, says Michael Kovrig and Michael Spavor are being arbitrarily and unjustly detained.

She says the U.S. is echoing Canada's calls for their immediate release.

Kovrig and Spavor have now spent two years in separate Chinese prisons on what Canada and dozens of its Western allies say are unfounded espionage charges.

China has faced accusations of so-called hostage diplomacy for acting in retaliation for the RCMP's December 2018 arrest in Vancouver of Chinese high-tech executive Meng Wanzhou on a U.S. extradition warrant.

The U.S. wants to extradite Meng on fraud charges.

Prime Minister Justin Trudeau recently spoke to U.S. president-elect Joe Biden about the "two Michaels," fuelling speculation that the Americans might be considering withdrawing their case against Meng, which could pave the way to freedom for the two Canadian men.

Brucker's statement made no mention of the Meng case.

"Dec. 10 marks International Human Rights Day and two years since the arbitrary and unjustified detention of Canadians Michael Kovrig and Michael Spavor by Chinese authorities," she said.

"We echo the calls from the Canadian government, the international community, and the families of Michael Kovrig and Michael Spavor for these two men to be released immediately and returned home."

Editors' note: An earlier version of this story included incorrect information about where Michael Kovrig and Michael Spavor stand in the legal process.