Familiar verbal duel between China and the US over South China Sea took on greater import with Secretary of State John Kerry saying the deployment of missiles on an island in the Paracel chain violated Chinese President Xi Jinping's assurance during his US visit last year.
"When President Xi was here in Washington, he stood in the Rose Garden with President Obama and said China will not militarise the South China Sea. But there is every evidence every day that there has been an increase in militarisation. It's a serious concern," Kerry said.
US said weapons deployment in South China Sea threatens free passage in an area through which ship-borne trade worth $5 trillion passes every year.
"We have said repeatedly with respect to China that the standard that should be applied to all countries with respect to the South China Sea is no militarisation," Kerry said.
China, in response, said the US was engaging in sensationalism. "It is hoped that the relevant country would stop pointless sensationalisation which has ulterior motives and do more to uphold regional peace and stability," Chinese Foreign Ministry spokesperson Hong Lei said.
China had earlier 'challenged' reports that it placed advanced surface-to-air missile launchers on the Woody islands in the Paracels. Beijing, however, did not deny weapons deployment on the island chain.
"The limited defensive facilities that China has deployed on its own territory have nothing do with militarization," China's top diplomat Yang Jiechi said.
Chinese Communist party mouthpiece Global Times also said China has deployed weapons on the island for a long time.
Two batteries of eight surface-to-air missile launchers and a radar system were deployed on Woody Island, which is claimed by China, Taiwan and Vietnam, Fox News had reported on Wednesday, citing images from ImageSat International.
China's defence activities in the disputed waters coincided with a summit President Barack Obama was holding with the Asean leaders, where he called for action to ensure freedom of navigation and a peaceful resolution of the maritime conflicts in the South China Sea.
US has no territorial claims in the South China Sea but it sees China's land reclamation near the island chains of Paracel and Spratlys and the building of airstrips as attempts to militarise the region.
In January, the two countries criticised each other after US navy's guided-missile destroyer USS Curtis Wilbur sailed near Triton Island in the Paracel Islands in the South China Sea.
While Washington said the operation was aimed at countering efforts to curb freedom of navigation in the region, Beijing said its defence vessels confronted the US ship in its territory and "expelled it swiftly".
Following the latest face off, the Global Times said China had the right to strengthen its "self-defence" in the South China Sea in the backdrop of provocations from the US military.
"Jet fighters from the US, an outside country, may feel uneasy when making provocative flights in the region. To us, that's a proper result."