Last week, Philippines General Gregorio Catapang told reporters that China's reclamation in the area is "50 percent complete".
"It is alarming in the sense that it could be used for other purposes other than for peaceful means," he said.
China reiterated that Beijing had "indisputable sovereignty" over the Spratly Islands, where most of the overlapping claims lie, especially between China and the Philippines.
"China's actions on the relevant islands and reefs are all matters within the scope of China's sovereignty," Foreign Ministry spokesman Hong Lei told a daily news briefing.
Aerial images from the Philippines military and a leading U.S. defense publication show China is developing an airstrip on one of the islands.
The construction has stoked concern that China may be converting disputed territory in the archipelago into military installations.
Read more at Reuters
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