WASHINGTON — The Chinese government has detained a third Canadian citizen, escalating a diplomatic crisis in which it is pushing the United States to relent on legal pressure against one of China’s leading technology companies.

Canadian consular officials are providing assistance to the family of the latest detainee, a spokesman for Global Affairs Canada, the country’s foreign ministry, said on Wednesday. The spokesman declined to identify the detainee or provide more details.

A Chinese Foreign Ministry spokeswoman, Hua Chunying, said at a regularly scheduled news conference in Beijing on Wednesday that the ministry had no information on the case.

Chinese security agencies detained two other Canadians, Michael Kovrig and Michael Spavor, on Dec. 10. Chinese officials have suggested in public comments that the agencies are looking into potential national security charges.