"We are concerned by the increase in tensions in the South China Sea and are monitoring the situation closely," State Department spokesperson Patrick Ventrell said.
Recent developments include an uptick in confrontational rhetoric, disagreements over resource exploitation, coercive economic actions, and the incidents around the Scarborough Reef, including the use of barriers to deny access, he said.
In particular, China's upgrading of the administrative level of Sansha City and establishment of a new military garrison there covering disputed areas of the South China Sea run counter to collaborative diplomatic efforts to resolve differences and risk further escalating tensions in the region, the US official noted.
The US, he said, urged all parties to take steps to lower tensions in keeping with the spirit of the 1992 ASEAN Declaration on the South China Sea and the 2002 ASEAN-China Declaration on the Conduct of Parties in the South China Sea.
"We strongly support ASEAN's efforts to build consensus on a principles-based mechanism for managing and preventing disputes. We encourage ASEAN and China to make meaningful progress toward finalising a comprehensive Code of Conduct in order to establish rules of the road and clear procedures for peacefully addressing disagreements," he said.
In this context, the United States endorses the recent ASEAN Six-Point Principles on the South China Sea, he added.
Urging all parties to clarify and pursue their territorial and maritime claims in accordance with international law, including the Law of the Sea Convention, he said the US believes that claimants should explore every diplomatic or other peaceful avenue for resolution, including the use of arbitration or other international legal mechanisms as needed.
"We also encourage relevant parties to explore new cooperative arrangements for managing the responsible exploitation of resources in the South China Sea," he said.
Ventrell said as a Pacific nation and resident power, the US has a national interest in the maintenance of peace and stability, respect for international law, freedom of navigation, and unimpeded lawful commerce in the South China Sea.
"We do not take a position on competing territorial claims over land features and have no territorial ambitions in the South China Sea; however, we believe the nations of the region should work collaboratively and diplomatically to resolve disputes without coercion, without intimidation, without threats, and without the use of force," he said.
Washington: Concerned over the establishment of a new military garrison by China in the South China Sea, the US on Friday said it was monitoring the situation and asked all stake holders to lower tension in the disputed waters.
First Published: Friday, August 03, 2012, 19:59