By Megha Rajagopalan
BEIJING (Reuters) - China outlined its defense strategy to boost its naval capability farther from its shores on Tuesday, saying it faced a grave and complex array of security threats including in the disputed South China Sea.
In a policy document issued by the State Council, the Communist-ruled country's cabinet, it vowed to increase its "open seas protection", switching from air defense to both offence and defense, and criticized neighbors who take "provocative actions" on its reefs and islands.
The document comes as tensions rise over China's increasingly assertive posture in the disputed waters of the South China Sea, where Beijing has engaged in land reclamation in the Spratly archipelago.
China, which claims most of the South China Sea, criticized Washington after a U.S. spy plane flew over areas near the reefs last week, with both sides accusing each other of stoking instability.
It has overlapping claims with the Philippines, Vietnam, Malaysia, Taiwan and Brunei in the South China Sea, through which $5 trillion in ship-borne trade passes every year.
The document triggered a sharp rise in defense stocks, with many rising their maximum 10 percent daily limit, including China Satellite, Sichuan Chengfei Technology Integration and AVIC Aircraft.
Defense Ministry spokesman Yang Yujun said China's reclamation activities in the Spratly archipelago were comparable with construction of homes and roads on the mainland.
"From the perspective of sovereignty, there is absolutely no difference," he told reporters.
Some countries with "ulterior motives" had unfairly characterized China's military presence and sensationalized the issue, he said. Surveillance in the region was increasingly common and China would continue to take "necessary measures" to respond.
"Some external countries are also busy meddling in South China Sea affairs. A tiny few maintain constant close-in air and sea surveillance and reconnaissance against China," the strategy paper said in a thinly veiled reference to the United States.
It also said China's air force would shift its focus from territorial air defense to both offence and defense, and building airspace defenses with stronger military capabilities.
Taiwan President Ma Ying-jeou called on claimants to the sea to temporarily shelve their disagreements to enable talks on sharing resources before a conflict breaks out.
The People's Liberation Army's nuclear force, known as the Second Artillery Corps, would also strengthen its capabilities for deterrence and nuclear counterattack as well as medium- and long-range precision strikes, the paper said.
The paper said modernizing and strengthening maritime military forces were critical to national security and overseas interests.
"China faces many complex maritime security threats and challenges and requires a navy that can carry out multifaceted missions and protect its sovereignty," Wang Jin, a senior colonel, told reporters.
The paper also cited "grave threats" to China's cyber infrastructure, adding that China would hasten development of a cyber military force.
(Reporting By Megha Rajagopalan, additional reporting by Pete Sweeney in SHANGHAI; Editing by Paul Tait and Nick Macfie)