The Chinese planes shadowed the Canadian Aurora aircraft over several hours in international waters, with one coming within five meters (15 feet) of the Canadian plane, according to a Global News television crew on the flight.

Speaking to reporters in Ottawa, Defense Minister Bill Blair called the Chinese air force's actions "unprofessional."

"It was, quite frankly, dangerous and reckless," he said, adding that his concerns would be conveyed to Beijing.

The Aurora aircraft and its 13-member crew have been tasked with supporting a multinational effort to implement UN Security Council sanctions against North Korea in response to its nuclear weapons tests and ballistic missile launches.

Relations between Ottawa and Beijing hit a new low this year amid accusations of Chinese meddling in Canadian elections and the attempted intimidation of MPs that led to the expulsion of a Chinese diplomat in May.

Beijing called the accusations "groundless," and responded by sending home a Canadian diplomat from the country's consulate in Shanghai.

Bilateral ties were already strained over the arrest of a senior Chinese telecom executive on a US warrant in Vancouver in December 2018 and Beijing's retaliatory detention of two Canadians on espionage charges.

All three were released in September 2021 after a deal with US prosecutors was struck on the charges against the Huawei executive.