Beijing has placed surface-to-air missiles on a contested South China Sea island, raising tensions. China has deployed at least two batteries of eight missile launchers on Woody Island, which is claimed by both Taiwan and Vietnam.
According to Fox News, which first reported the development, citing images from a civilian satellite, a radar system has also been mobilised in the area. According to a US official cited by the television channel, China has deployed the HQ-9 air defence system, which has a range of about 200km.
Taiwan's defence ministry confirmed the deployment and said it is closely watching the situation. "Interested parties should work together to maintain peace and stability in the South China Sea region and refrain from taking any unilateral measures that would increase tensions," Taiwan defence ministry spokesperson Major General David Lo told Reuters.
The US has not confirmed or denied the deployment and was expected to respond shortly. Chinese Foreign Minister Wang Yi was also scheduled to address a press conference in Beijing.
Recently, a US navy destroyer sailed close to Woody island prompting sharp condemnation from Beijing. At that time, China vowed to respond with serious consequences and said the US was "the biggest cause of militarisation in the South China Sea".
On the eve of the latest revelations, a Chinese foreign ministry spokesperson, Hong Lei, reiterated Beijing's commitment to protecting its sovereign territories. Hong said: "Deploying necessary national defence facilities on its own territory is China's exercise of self-preservation and defence, a right granted by international law to sovereign states. It does not impede freedom of navigation and overflight in the South China Sea that all countries are entitled to under international law."
The South China Sea archipelago consists of about 750 islands and reefs believed to be rich in oil and gas resources. The chain of islands has been at the centre of an international dispute in recent years with China claiming almost the entire region. Multiple countries including Taiwan, Japan, the Philippines and Vietnam have overlapping claims.