Beijing —
China’s military on Monday condemned the sailing of a Canadian warship in the Taiwan Strait, saying its air and naval forces had monitored and warned the ship, a mission that came just a few days after U.S. Navy ships made a similar mission.

The U.S. Navy, and occasionally ships from allied countries like Canada, Britain and France, transits the strait around once a month. China, which claims Taiwan as its own territory, also says the strategic waterway belongs to it.

Canada’s actions “deliberately stirred up trouble” and undermined peace and stability in the strait, the People’s Liberation Army’s Eastern Theater Command said in a statement.

“Theater forces maintain a high level of alert at all times and resolutely counter all threats and provocations,” it added.

The Canadian military declined immediate comment.

Both the Chinese and Taiwanese governments identified the ship as the Ottawa.

Taiwan’s military ministry stated on Sunday that the ship had proceeded north, and that Taiwanese Marines were also on patrol. Taiwan’s foreign ministry applauded the sailing. “Canada has once again taken concrete actions to defend the freedom, peace and openness of the Taiwan Strait and has demonstrated its firm position that the Taiwan Strait is international waters,” according to a statement issued Sunday. Taiwan has complained about recurrent Chinese military activity near the island. Taiwan’s defense ministry reported Monday morning in its daily briefing on China’s actions over the previous 24 hours that 41 Chinese military aircraft and nine ships had been observed around the island, with the majority concentrated in the strait and off Taiwan’s southwest. Last October, a US and a Canadian warship sailed together through the strait, less than a week after China conducted a new round of war games around the island.

Taiwan’s democratically elected administration opposes Beijing’s sovereignty claims, claiming that only the island’s people can determine their own future.