HANOI (Reuters) - Vietnam lodged a formal protest with China and the United Nations chief on Friday, saying it was "deeply concerned" over Beijing's apparent deployment of an advanced surface-to-air missile system on a disputed island in the South China Sea.
"These are serious infringements of Vietnam's sovereignty over the Paracels, threatening peace and stability in the region as well as security, safety and freedom of navigation and flight," Foreign Ministry spokesman Le Hai Binh said in a statement.
The statement, sent to Reuters, said diplomatic notes had been issued to China's embassy in Hanoi and to the United Nations Secretary General Ban Ki-moon to protest Beijing's activities.
Taiwan and U.S. officials said on Wednesday the missile system had been deployed to Woody island, which is part of the China-controlled Paracel chain that Vietnam and Taiwan also claim sovereignty over.
At a summit of Southeast Asian leaders in California on Monday, Vietnam Prime Minister Nguyen Tan Dung suggested to U.S. President Barack Obama that Washington take "more efficient actions" against militarization and island-building in the South China Sea.
(Reporting by Martin Petty and Ho Binh Minh; Editing by Alex Richardson)