US President Joe Biden and Canadian Prime Minister Justin Trudeau on Monday discussed China's "arbitrary detention" of two Canadian citizens.
In a telephone conversation, the two leaders discussed Beijing's two-year detention of former Canadian diplomat Michael Kovrig and Canadian businessman Michael Spavor, who are both being held on charges of spying.
"The Prime Minister and the President discussed China's arbitrary detention of Canadian citizens Michael Spavor and Michael Kovrig. The leaders agreed on the need for their immediate release," a press release from Trudeau's office said.
The two men were detained in apparent retaliation for Canada's arrest on a US extradition warrant of Huawei executive Meng Wanzhou.
A statement from Biden's office said Spavor and Kovrig had been "unjustly detained" and that during the call, the president had condemned their detention and "reiterated his commitment to stand strong with Canada to secure their release."
Ottawa has said they were taken as virtual hostages to apply pressure in the Huawei executive's case.
The two men first appeared in court in March this year, in hearings that wrapped up quickly.
Meng, 49, is due to be back in a Canadian court on Wednesday for a final round of hearings on her possible extradition to the United States, after nearly three years of court battles and diplomatic sparring.
If transferred to the United States for trial and subsequently convicted, she could face more than 30 years in a US prison.
Both the Chinese government and Huawei, the world's largest supplier of telecom networking gear, have consistently denied the US accusations.
Beijing has charged that Washington's primary aim in pursuing Meng is to weaken Chinese tech companies, calling the whole case "a serious political incident."