From China’s official Ministry of Foreign Affairs (MFA) website: Spokesperson Geng Shuang's Regular Press Conference, April 20, 2020 https://www.fmprc.gov.cn/mfa_eng/xwfw_665399/s2510_665401/2511_665403/t1771576.shtml
Pete
[Question] Reuters [journalist asks]: Vietnam has said China's claim to have established administrative units on islands in the South China Sea seriously violates Vietnam's sovereignty. What's your comment on this?
[Answer from] Geng Shuang: Following the approval of the State Council, Sansha City of Hainan Province has established two districts, Xisha District [Paracel Islands] and Nansha District [Spratly Islands]. This is China making administrative division adjustment within the scope of its sovereignty. It is conducive to improving and enhancing Sansha City's administrative management and promoting the coordinated development of the city's economic growth and environment protection.
China has sovereignty over the Xisha and Nansha Islands and their adjacent waters, and sovereign rights and jurisdiction over the relevant waters and the seabed and subsoil thereof. In accordance with domestic laws and regulations, the Chinese government has selected and published the names of some islands and reefs of the Xisha and Nansha Islands as well as the seabed of waters under its jurisdiction. This is what we do regularly in accordance with law to improve marine management, which also accords with international law and international practices.
China firmly opposes Vietnam's words and actions that undermine China's sovereignty and rights and interests in the South China Sea, and will continue to take necessary measures to firmly safeguard China's sovereignty and rights and interests.
The Sansha City capital, on Woody Island, is marked, as well as the Spratlys and Paracels - all claimed by China and US supported Taiwan.
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Nine-Dash Line illustrated by red line covering most of the South China Sea, is claimed by China and Taiwan. But only China has the strategic power, allied with infrastructue capability, to enforce the claim. (Map courtesy Voice of America, 2012)
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THE TERM NINE-DASH LINE - ORIGINATED WITH US SUPPORTED ROC/TAIWAN
The term nine-dash line - at various times also referred to as the ten-dash line and the eleven-dash line – was used initially by the Republic of China (ROC, 1912–1949) and subsequently by Taiwan and China, for their claims of the major part of the South China Sea.
Taiwan has continued its claims, and the nine-dash line remains as the rationale for Taiwan's claims to the Spratly and Paracel Islands.
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SANSHA CITY
Sansha is a prefecture-level city of China’s Hainan province. Sansha City capital is located on Woody Island and administers (actually or nominally) several island groups and undersea atolls in the South China Sea including the Spratly Islands, the Paracel Islands, Macclesfield Bank, Scarborough Shoal, and a number of other ungrouped maritime features.
In November 2016, the Hainan government started to allow large companies to register themselves in Sansha, by providing extensive tax benefits to them. This resulted in 157 large national and multinational companies registering themselves in Sansha.
In 2016, a government school and a public library were opened in the island, primarily for children of the islanders. In the same year, a desalinating plant was established to provide drinking water to the island's residents.
Airports are built on several islands in Sansha City, including Yongxing Island (Woody Island), Meiji Island (Mischief Reef, Spratlys), Yongshu Island (Fiery Cross Reef, Spratlys) and Zhubi Island (Subi Reef, Spratlys), all of which are theoretically capable of landing Boeing 777s as diversion airports. In practice, only Woody Island has scheduled commercial services, with a Boeing 737 operated by Hainan Airlines.
Sansha City capital, Woody Island above (with critical installations above - courtesy Digital Globe) and clear overhead photo of Woody Island, with later land reclamation work for civilian/naval harbours (below).
Pete