Hanoi has asked Beijing to withdraw military equipment that it reportedly deployed in the South China Sea, according to the country's Foreign Ministry.
"Vietnam requests that China, as a large country, show its responsibility in maintaining peace and stability in the East Sea," the ministry's spokeswoman Le Thi Thu Hang said in a statement following reports in the media on Chinese military activity in the South China Sea.
"Militarization activities, including the installation of missiles on the Spratly islands, is a serious violation of Vietnam's sovereignty," she continued.
Vietnam's request comes after the CNBC reported earlier in May, citing sources in US intelligence, that Beijing had deployed anti-ship cruise missiles and surface-to-air missile systems on three of its military posts on the Spratly Islands — the Fiery Cross Reef, Subi Reef and Mischief Reef. The deployment, if confirmed, could mark the first installation of Chinese missiles in the South China Sea.
Beijing lays territorial claims to 90 percent of the maritime territory it calls the Nansha Islands, which are believed to be energy rich. Neighboring Asian countries, including the Philippines, Malaysia, Brunei and Taiwan, have rival claims to this territory, whereas Taiwan and Vietnam contest the Paracel Islands, known as the Xisha Islands in China.