The navies of the United States and Canada sailed two warships through the Taiwan Strait, prompting China to put its troops on “constant high alert.”
The US Navy said in a statement on Saturday that the guided-missile destroyer USS Ralph Johnson and Canada's HMCS Ottawa sailed through the waters that separate mainland China and Chinese Taipei.
The navy said the warships conducted a "routine" transit "through waters where high-seas freedoms of navigation and overflight apply in accordance with international law.”
China’s military condemned the transit, saying its troops "remain on constant high alert, and will resolutely protect national sovereignty and security as well as regional peace and stability."
China has sovereignty over the self-ruled island, and under the "One China" policy almost all world countries recognize that sovereignty.
China's military spokesperson Shi Yi said that the two ships had "openly hyped up" their passage through the strategic waters.
Chinese forces tracked both ships throughout their entire transit and "dealt with the situation,” Shi added.
A similar joint transit occurred in June when a Chinese navy ship cut sharply across the path of an American destroyer, forcing the US vessel to slow to avoid a collision.
The US ship also was conducting a transit with a Canadian vessel at the time.
The US Navy released a video of the joint sailing, describing it as an "unsafe interaction" in the Taiwan Strait.
China has been increasing its military operations around the island over the past few years, due to the United States and Western allies' provocations by naval vessels through both the Taiwan Strait and the South China Sea.