HANOI (Reuters) - China’s construction of a new platform in a remote part of the disputed South China Sea is a serious violation of Vietnam’s sovereignty, its foreign ministry said on Thursday.

The platform, which sits on the strategically-located Bombay Reef and was revealed in satellite images published this week by a U.S. think tank, which said the structure could be used for military purposes.

“The fact that China continues its activities in Vietnam’s Paracels has seriously violated Vietnam’s sovereignty on this archipelago,” foreign ministry spokeswoman Nguyen Phuong Tra told a news conference on Thursday.

“We vehemently object to this action by China and demand that China stop immediately, not repeat similar activities, and respect Vietnam’s sovereignty in accordance with international law,” said Tra.

Malaysia, the Philippines, Taiwan and Brunei also have competing claims in the South China Sea, which is known in Vietnam as the “East Sea”.

The strategic waterway is claimed almost in its entirety by China, whose continued building of military and other installations on artificial islands and reefs there has unnerved the region and angered Washington.

China’s foreign ministry spokesman Geng Shuang said on Wednesday that China’s sovereignty over the Paracel Islands was not in dispute, and there is nothing wrong with China carrying out construction work on its own territory.

The United States earlier this month again urged China to halt its militarisation of the South China Sea.