The map includes the Spratly island
chain, which is the subject of overlapping claims by China, Taiwan, Vietnam, Brunei, Malaysia and the Philippines.
China and the 10-member Association of South East Asian Nations have been working on a ''code of conduct'' to govern state activities in the South China Sea, where China, Vietnam, Malaysia, the Philippines and Brunei have conflicting claims over the sprawling Spratly island
Both China and Vietnam claim sovereignty over the Paracel and Spratly island
groups in the South China Sea, with both countries engaging in oil and gas exploration in overlapping maritime zones in the region.
The base in Cam Ranh Bay located about 460 km from the disputed Spratly Islands
, which is also claimed by China.
China's foreign ministry said authorities monitored and warned the USS Lassen as it entered what China claims as a 12-mile (20km) territorial limit around Subi Reef in the Spratly Islands
archipelago, where the Philippines has competing claims.
officials said they were considering maritime patrols within the 12-nautical-mile limit of the Spratly Islands
, which are claimed in part or in whole by multiple countries, including Vietnam, the Philippines, and China, which has been adding to the size of the islands by dredging up sand from the ocean floor.
Some analysts in Washington believe the United States has already decided to conduct freedom-of-navigation operations inside the 12-nautical-mile limits that China claims around islands built on reefs in the Spratly islands
Therefore, the littoral states of the South China Sea are right to resist Chinese expansionism onto the reefs and atolls of the Paracel and Spratly Islands
, that are nowhere near China's territorial waters.
The South China Sea dispute centers on the Spratly Islands
, a group of more than 750 islands and reefs, where China has been constructing artificial islands on coral reefs over the past few months, some with defense facilities.
China has angered the US by developing the Spratly Islands
, which lie on a busy Chinese shipping route.
Recent satellite images suggest China has made rapid progress in building an airstrip suitable for military use in contested territory in the Spratly islands
, which drew concern from the United States and its allies in Asia.
Recent satellite images published on Thursday show China has made rapid progress in building an airstrip suitable for military use in contested territory in the South China Sea's Spratly Islands
and may be planning another, moves that have been greeted with concern in the United States and Asia.