Spavor, a businessman based near the China-North Korea border, and Kovrig, a former Canadian diplomat and geopolitics researcher, were first detained by Chinese state security on December 10, a week after Canadian airport authorities detained senior Huawei executive Meng Wanzhou at the behest of US law enforcement.
Kovrig was arrested on suspicion of spying on state secrets for foreign entities and other intelligence crimes, while Spavor was held on suspicion of stealing state secrets to foreign entities, Lu said.
Days after Meng's detention was announced, China said it suspected Kovrig, who works for the International Crisis Group think tank, of spying and stealing state secrets and alleged that Spavor - who organized trips to North Korea - had provided him with intelligence.
"I need to make it clear to the Canadian side that, like we said on previous occasions, China has taken compulsory measures on the two Canadians in accordance with law", Lu added.
After months in detention, China has formally arrested two Canadians accused of espionage.
Canada has refused China's demand to release Meng.
After holding Michael Kovrig and Michael Spavor in an undisclosed locations since December, China's confirmation of the formal charges came just as the US government all but banned American companies from doing business with Chinese tech giant Huawei, a move that could badly cripple a firm considered by China to be a national symbol of industrial prowess.
Both men have been denied access to lawyers and allowed only monthly consular visits. Kovrig also holds Hungarian citizenship.
They were held days after Canada detained top Huawei executive Meng Wanzhou on a United States extradition request, which sparked assumptions that it was a retaliatory act by Beijing.
Meng, 47, is the daughter of Huawei Technologies Co Ltd's billionaire founder, Ren Zhengfei.
Meng is free on bail and a judge this month granted her request to move into a larger Vancouver multimillion-dollar home that recently underwent renovation.
The federal government is not taking any option off the table, as U.S. President Donald Trump is reportedly set to sign a new executive order to ban American companies from doing business with Chinese telecom giant Huawei.
She was arrested at Vancouver's airport in December on a US warrant and is fighting extradition on charges that she conspired to defraud global banks about Huawei's relationship with a company operating in Iran.
The U.S. has pressured other countries to limit their use of Huawei's technology, warning they could be opening themselves up to surveillance and theft of information.
Huawei Chief Financial Officer, Meng Wanzhou, leaves her residence to attend British Columbia Supreme Court, in Vancouver, on May 8, 2019. His case is now under appeal.
Public Safety Minister Ralph Goodale said Canadians thinking of travelling to China should consult with Global Affairs Canada.