MANILA: The Philippines on Wednesday accused China of undertaking massive reclamation work on several reefs in the disputed waters of South China Sea, expressing concern the activities could fuel tensions.

The United States meanwhile called for restraint in the territorial conflict. Philippine and US officials spoke as the longstanding allies ended a two-day strategic dialogue in Manila, reaffirming defense and economic cooperation.

“The Chinese activities in the West Philippine Sea (South China Sea) continue to be a serious concern, arising from reports of greater development in reclamation,” Philippine defence undersecretary Pio Lorenzo Batino told reporters.

Batino refused to elaborate on the progress of the reclamation, saying only: “It’s very serious. It has grown.”

Evan Garcia, Manila’s deputy foreign minister, said the reclamation activities “are not a positive development to promote our common interests” and a clear violation of what had been agreed by China and Southeast Asian states in 2002.

“It is not helpful in finding a way forward. It is not an example of what everyone would understand as self-restraint,” Garcia said.

The Philippines last year accused China of blasting sand and rocks to reclaim areas around reefs in the sea. Facilities under construction reportedly include an airstrip.

The United States has “laid out a persuasive case for restraint” in the South China Sea, said assistant secretary of state Daniel Russel, calling the territorial disputes an “ongoing concern.”

“We believe bigger nations can’t bully the small,” he said.

“We have a huge interest in stable, healthy, constructive bilateral relations with China,” Russel said, but the US was also concerned about “behaviour that raises tensions, behavior that raises questions about China’s intentions.”