- USS Decatur destroyer was conducting "freedom of navigation operation"
- A Chinese Luyang destroyer approached within 45 yards of Decatur's bow
- The encounter took place in contested waters in the South China Sea
A Chinese warship sailed within yards of an American destroyer -- forcing it to change course -- in an "unsafe and unprofessional" encounter as the US vessel was in contested waters in the South China Sea, an official said Monday.
The USS Decatur guided-missile destroyer was conducting what the military calls a "freedom of navigation operation" Sunday, when it passed within 12 nautical miles of Gaven and Johnson reefs in the remote Spratly Islands.
The 12-mile distance is commonly accepted as constituting the territorial waters of a landmass.
Beijing claims all of the Spratly chain as part of its sweeping claims across much of the South China Sea.
During the operation, a Chinese Luyang destroyer approached the USS Decatur in "an unsafe and unprofessional maneuver in the vicinity of Gaven Reef in the South China Sea," US Pacific Fleet spokesman Commander Nate Christensen said.
The Chinese ship then conducted a series of "increasingly aggressive maneuvers, and warned the Decatur to depart the area," he added.
The Chinese "destroyer approached within 45 yards (meters) of Decatur's bow, after which Decatur maneuvered to prevent a collision."
US-Chinese relations have been strained on multiple levels since Donald Trump became president in 2017.
A trade war launched by Trump has infuriated Beijing, as did his authorization of a $1.3 billion arms sale to Taiwan, which China considers a rebel province.
Washington last week enacted new tariffs against China covering another $200 billion of its imports.
China has taken a series of retaliatory measures, including by scrapping a US warship's planned port visit to Hong Kong and canceling a meeting between the head of the Chinese navy and his American counterpart.
On Monday, a US defense official said that security talks due to take place later this month in Beijing between Defense Secretary Jim Mattis and his Chinese counterpart had been canceled.