LONDON — Two Canadian nationals detained in China were arrested and accused of espionage Thursday, a move that risks exacerbating a diplomatic dispute between the two countries that started with Canada's arrest of a Huawei executive last year.

Michael Kovrig, a former Canadian diplomat, was arrested on "suspicion of spying on state secrets and intelligence for overseas," China's Ministry of Foreign Affairs spokesman Lu Kang told a press briefing Thursday. And Michael Spavor, an entrepreneur based in China, was arrested on "suspicion of stealing and illegally providing state secrets to overseas," Lu added.

The two men were detained separately last December on suspicion of “endangering national security” — a vague accusation that encompasses both traditional espionage and other forms of information gathering, such as interviewing political dissidents and contacting nongovernmental organizations. But they were only formally arrested on Thursday.

The Canadian government condemned what it described as Kovrig and Spavor's "arbitrary arrest" and demanded that they be immediately released.

The pair were first detained last December in an apparent retaliation for Canada’s arrest of Meng Wanzhou, chief financial officer of the Chinese telecommunications giant Huawei, last December. Wanzhou was arrested at the request of the United States, which wants her extradited to face charges that she and her company misled banks about the company’s business dealings in Iran. She is still being held in Canada.

It is unclear if the Spavor or Kovrig know each other or have ever met. Spavor organizes tours to North Korea through his company Paektu Cultural Exchange. He was instrumental in bringing ex-NBA player Dennis Rodman to Pyongyang in 2013 and has organized a number of joint cultural projects with the North since then.

The arrests come amid growing tensions between the U.S. and China and some of its major technology and telecommunications companies.

President Donald Trump declared a national emergency over foreign threats to U.S. communications infrastructure and services, issuing an executive order Wednesday that gave Wilbur Ross, the secretary of commerce, the ability to block companies deemed a national security threat. No specific countries or companies were mentioned in the order.

But shortly thereafter, the Department of Commerce announced that it would be adding Huawei to its "Entity List," meaning any Huawei business in the U.S. will now require approval from the Commerce Department's Bureau of Industry and Security.

Huawei said in a statement Thursday: "We are ready and willing to engage with the @USAGov and come up with effective measures to ensure product security. Restricting Huawei from doing business in the U.S. will not make the U.S. more secure or stronger."