Source: BBCNews
Chinese officials have condemned a US ship's passage near disputed islands in the South China Sea as "illegal" and a threat to their country's sovereignty.
The guided-missile destroyer USS Lassen breached the 12-nautical mile zone China claims around Subi and Mischief reefs in the Spratly archipelago.
The US has confirmed the operation took place, apparently as part of its Freedom of Navigation programme.
The operation is a challenge to China's claims over the artificial islands.
Lu Kang, a spokesman for China's foreign ministry, said Beijing would "resolutely respond to any country's deliberately provocative actions".
He added that the ship had been "tracked and warned" while on the mission to deliberately enter the disputed waters.
The Chinese foreign ministry summoned the US ambassador to protest over the move.
Meanwhile, US Defence Secretary Ash Carter confirmed that the USS Lassen had passed within 12 miles of the islands, during questioning by the Senate Armed Forces Committee.
US Defence Department spokesman Cdr Bill Urban had earlier said that "the United States is conducting routine operations in the South China Sea in accordance with international law".
The move was welcomed by several countries in the East Asia region, including the Philippines and Japan.
China claims most of the South and East China seas. Other countries in South-East Asia have competing claims for the Spratly Islands, Paracel Islands and Scarborough Shoal, which are thought to have resource-rich waters around them.
The reefs, which were submerged, were turned into islands by China by a massive dredging project which began in late 2013.
China says this work is legal and in a meeting with US President Barack Obama last month in Washington, President Xi Jinping said China had "no intention to militarise" the islands.
But Washington believes Beijing is constructing military facilities, designed to reinforce its disputed claim to most of the region - a major shipping zone.