The United States and China showed no sign of bending in their positions over Chinese land reclamation projects in the South China Sea, as China's foreign minister told top US diplomat that Beijing was "unshakeable" in its defence of sovereignty.
US Secretary of State John Kerry met with his Chinese counterpart Wang Yi in Beijing on Saturday, and urged China to take action to reduce tension in disputed waters, saying the US is concerned by the pace and scope of China's reclamation projects.
Wang's response was firm: "The determination of the Chinese side to safeguard our own sovereignty and territorial integrity is as firm as a rock and it is unshakeable."
Kerry also said the region needed "smart diplomacy", rather than "outposts and military strips" during a press conference with Wang, reminding two countries have significant commercial ties.
Tensions between the powers mount over Chinese artificial island-building in strategic waters, as Washington decided to send a littoral combat ship last week to patrol the area.
The US dispatched a reconnaissance drone and a Seahawk helicopter to patrol the airspace above the South China Sea, while the USS Fort Worth, one of the most modern ships in the US navy, was sent to check the territorial waters around the Spratly islets where China reasserts its continental shelf.
China claims about 90 percent of the sea and it has long been confronting with its maritime neighbours Taiwan, Malaysia, the Philippines, Vietnam and Brunei.
A series of high-resolution satellite images show that China has intensified the construction of artificial islands in the disputed sea, sometimes doubling or tripling the size of existing features.
China rejects "US interference" in the region and wants to negotiate with the neighboring countries bilaterally.