Feb. 11 (UPI) -- Two U.S. Navy guided-missile destroyers sailed within 12 nautical miles of a disputed artificial island in the South China Sea on Monday, prompting "strong dissatisfaction" from China.
The USS Spruance and USS Preble -- both Arleigh Burke-class destroyers -- participated in what the U.S. Navy calls a "freedom of navigation operation," according to a statement by Cmdr. Clay Doss, a spokesman for the U.S. Navy's Seventh Fleet, obtained by ABC News.
"Spruance and Preble sailed within 12 nautical miles of the Spratly Islands in order to challenge excessive maritime claims and preserve access to the waterways as governed by international law," Doss said about the two ships, which are homeported in San Diego.
Doss confirmed the sailings to CNN.
"All operations are designed in accordance with international law and demonstrate that the United States will fly, sail and operate wherever international law allows," Doss said. He noted "that is true in the South China Sea as in other places around the globe."
Mischief Reef is one of seven artificial islands built up by China over the last five years. China has developed a military infrastructure, including long runways used by jet fighters and deploying anti-aircraft missiles, on what had been low-lying reefs.
International waters are considered 12 nautical miles from land.
"We conduct routine and regular Freedom of Navigation Operations, as we have done in the past and will continue to in the future," the Navy spokesman said in the statement to ABC. "FONOPs are not about any one country, nor are they about making political statements."
On Monday, Chinese foreign ministry spokeswoman Hua Chunying said its Navy warned the ships against approaching Chinese-claimed territory in the Spratly Islands.
"Under such circumstances, the U.S. insistence on provocation, creating tensions and destroying the peace and stability of the South China Sea is unpopular," she said in a report by the South China Morning Post. "China urges the U.S. to immediately stop such provocative actions and earnestly respect the efforts by regional countries to maintain the peace and stability of the South China Sea."
In January, the destroyer USS McCampbell sailed within 12 nautical miles of the Paracel Islands.
In late September, the USS Decatur also sailed within 12 nautical miles of Gaven and Johnson reefs in the Spratly Islands.
China has criticized both encounters.
"China has always respected and safeguarded freedom of navigation and flight based on international laws in the South China Sea, but resolutely opposes any country falsely using these harm the sovereignty and security of coastal countries," Hua said Monday.
In October, the destroyer USS Decatur had to maneuver to avoid a collision with a Chinese warship that came within 45 yards of its bow.
Beijing and several of its neighbors, including Malaysia, the Philippines, Vietnam and Taiwan, claim the South China Sea.
This week, China and the United States are planning a new round of trade talks in Beijing. They are facing a March 1 deadline in which the United State has threatened to increase tariffs on $200 billion worth of Chinese imports.