BEIJING - China on Friday said its construction work in the disputed West Philippine Sea (South China Sea) was conducted "within its territory" and "legal" amid criticism by the United States and the Philippines.
Recent satellite images show that China has made rapid progress in building an airstrip suitable for military use in contested territory in the Spratly Islands and may be planning another.
IHS Jane's Defence Weekly said March 23 images from Airbus Defence and Space showed work on the runway on reclaimed parts of Fiery Cross Reef in the Spratly archipelago, which China contests with the Philippines, Vietnam, Malaysia, Brunei and Taiwan.
The report comes a day after the U.S. military commander for Asia, Admiral Samuel Locklear, said China, which claims most of the South China Sea, could eventually deploy radar and missile systems on outposts it is building that could be used to enforce an exclusion zone should it move to declare one.
Philippine President Benigno Aquino also called on Friday the territorial dispute with China in the South China Sea a concern for the world because global trade will be hit by China's reclamation.
China said the move was not targeted at any other country.
"The relevant construction is conducted within China's sovereign territory, it is reasonable, understandable and legal, and it is not targeting or affecting any other country. We hope relevant countries and relevant sides can put it into perspective," Foreign Ministry spokesman Hong Lei told a regular news conference in Beijing.
About two dozen activists held a sit-down protest in front of the Chinese embassy in Manila on Friday to condemn Beijing's recent activities in the South China Sea.
Protesters carried banners and chanted nationalist slogans, urging China to stop its reclamation projects in the disputed islands.
"The Chinese aggression in the West Philippine Sea is proof that China does not resort to the peaceful and amicable settlement of dispute. China would rather use its bullying force against a small country like the Philippines. We challenge China - if you have any evidence at all of your claim in the West Philippine Sea, go to the tribunal, show your evidence," said Filipino lawmaker Neri Colmenares, who leads the left-leaning group Bayan Muna.
China claims most of the potentially energy-rich South China Sea, through which $5 trillion in ship-borne trade passes every year, and denies accusations its actions in its own territory are provocative.
On Wednesday, G7 foreign ministers issued a statement on maritime security, expressing concern on unilateral actions in the South China Sea, including "large scale reclamation, which change the status quo and increase tensions".
American and Filipino troops will take part in the largest-ever drills in 15 years next week, a key component of America's rebalance to Asia policy.
In 2013, Manila filed an arbitration case at the The Hague questioning Beijing's "nine-dash-line" claims. The Philippines expects a ruling by 2016, while China has elected not to participate in the case.