Canadian Prime Minister Justin Trudeau says China's detention of a former diplomat and a businessman is "arbitrary".
The two Canadians were both arrested in China days after the arrest of Chinese tech giant Huawei's chief financial officer, Meng Wanzhou, in Vancouver. Meng is due to appear in a Canadian court for an extradition hearing related to charges of fraud and breaching sanctions against Iran.
Both Canadians held in China are accused of spying and gathering sensitive information.
They face charges of endangering China's national security.
Al Jazeera's Gabriel Elizondo reports from New York on the straining ties between Beijing and Ottawa.
