Reuters, Washington :China has reclaimed more land in the disputed Spratly islands of the South China Sea than previously known, according to a new Pentagon report, which says Beijing is also completing construction of a runway on one of its seven man-made outposts. Once the airstrip on Fiery Cross Reef is operational, China could potentially use it as an alternative runway for carrier-based planes, allowing the Chinese military to conduct “sustained operations” with aircraft carriers in the area, the report said.China’s sole aircraft carrier, a Soviet-era ship bought from Ukraine and refitted in China, has carried out exercises in the South China Sea but is not yet fully operational. Some experts believe China will deploy domestically built carriers by 2020 as part of plans to develop an ocean-going “blue water” navy.At the reclamation sites in the Spratlys where China is in the building phase, it has excavated deep channels and constructed new berthing areas to allow access for larger ships, said the report, called the Asia-Pacific Maritime Security Strategy.”The infrastructure China appears to be building would enable it to establish a more robust power projection presence into the South China Sea,” it added.