China on Thursday unveiled details of its plan for building and maintenance projects on some of its islands in the South China Sea, saying it aims mainly to provide a civilian service that will benefit other countries.
The details were announced by the Foreign Ministry, which also accused Washington of adopting double standards on the issue by ignoring building work by other countries on islands owned by China.
Foreign Ministry spokeswoman Hua Chunying said at a regular news briefing, "We are setting up shelters, aids for navigation, search and rescue as well as marine meteorological forecasting services, fishery services and other administrative services.
"These will provide necessary services to China, neighbouring countries and individual vessels sailing in the South China Sea."
Hua said the construction work also aims to meet "necessary demands" for China's military defence, but the efforts "are aimed more at providing civilian services" in an area that suffers frequently from typhoons and where many vessels sail far from land.
"The construction work is a matter that is entirely within the scope of China's sovereignty. It is fair, reasonable and lawful. It does not affect, and is not targeted against, any country. It is beyond reproach," Hua said.
Reuters said in a report on Thursday, "It is rare for China to give such detail about its plans" on such construction work.
Luo Yongkun, a researcher specialising in Philippine studies at the China Institute of Contemporary International Relations, said Beijing has made a "friendly gesture" by disclosing details of construction work on its territory to assure its neighbours and remove any misunderstandings.
United States Defence Secretary Ashton Carter, who is visiting Asia this week, has said he is "especially concerned" about construction work by China on the islands.
Carter told reporters before leaving Japan for South Korea, "It's not just an American concern, but a concern of almost every country in the entire region."
The Philippines and Vietnam have long carried out construction work on China's islands in the area, but Hua said the US has remained silent on this.
In late March, Robert Thomas, commander of the US Navy 7th Fleet, suggested in Malaysia that Southeast Asian countries form a combined maritime force to patrol areas of the South China Sea, and promised support from his fleet.
Hua said on Thursday that "recent erroneous and negative comments made by individual countries" have missed the point.
"China adheres to the path of peaceful development and carries out a defensive national defence policy. Maintaining peace and stability in the South China Sea is in line with the development and security of China."
A commentary by Xinhua News Agency said, "The latest breach of the US commitment not to take sides on the South China Sea issue" has been demonstrated by "irresponsible" remarks.