China has formally arrested two Canadian citizens it is believed to be holding to pressure Canada into releasing a Chinese telecoms executive. The move brings the two closer to trial on vaguely defined state security charges.

Chinese Foreign Ministry spokesman Geng Shuang said Thursday that Michael Kovrig and Michael Spavor have been arrested for allegedly stealing state secrets.

Geng gave no other details. Kovrig is a former Canadian diplomat and expert at the International Crisis Group, and Spavor is a businessman with lengthy experience in North Korea.

Both were arrested on Dec. 10 after Meng Wanzhou, an senior executive with telecoms giant Huawei, was arrested in Vancouver, Canada, on Dec. 1 at the request of U.S. authorities who want her extradited to face fraud charges.