These are the surface-to-air missiles China just apparently deployed into the South China Sea

This image with notations provided by ImageSat International N.V., shows satellite images of Woody Island. Photo / AP

China has apparently deployed an advanced surface-to-air missile system onto a disputed island in the South China Sea, according to US and Taiwanese officials.

The deployment was first reported by Fox News after Fox obtained satellite imagery detailing the equipment on the eastern part of Woody Island in the Paracel Island chain. In late January, a US guided missile destroyer passed within 12 miles of Triton Island in the same chain, in what is known as a freedom of navigation patrol. The exercise drew condemnation from China at the time. According to the imagery, the missiles were emplaced sometime between Febraury 3 and February 14.

Both Taiwan and Vietnam have claimed Woody Island as their own.

The missiles, known as the HQ-9, are a variant much like the United States Patriot missile battery and the Russians S-300. Both systems can engage targets at what is known as a "beyond the horizon" range using a set of sensors and radars that allow missiles to track and hit targets more than 100 miles away from the launch site. The HQ-9 is mounted to a truck chassis, which allows it be highly mobile when not in use.

"From their perspective this is a defense system designed to protect their sovereign territory," said Neil Ashdown, a deputy editor at IHS Janes, a military research group.

Not only can the HQ-9 hit aircraft, but like the S-300 and Patriot, it can also hit ballistic missiles. The system can also engage targets at more than 80,000 feet high.

The deployment of advanced surface-to-air systems has been the go-to move for countries to project their military might in recent months, and it seems China has ripped a page out of Russia's playbook. In December, following the shoot-down of a Russian strike fighter by Turkish F-16s, Russia deployed S-400 missile systems onto their airbase in northern Syria.

According to Ashdown, the decision to deploy the HQ-9 is more a symbolic move than a military escalation. The Chinese could have deployed other systems that were less high-profile than the HQ-9, which is just short of the deployment of land-based anti-ship cruise missiles, something Ashdown believes would be an extremely aggressive move on China's behalf.

Regardless of the Chinese government's intent, the HQ-9 could be the first part of a deployment of systems that could create a sophisticated anti-access/anti-denial (A2/AD) network in the region. In short, the HQ-9 could interface with other systems to create a sort of defensive bubble over the disputed island chains, making any type overflight for U.S. aircraft extremely dangerous and problematic in the event of an actual conflict.

"[The deployment of the HQ-9] reflects a harder step by Beijing towards these Maritime claims," said Ashdown. "This is a harder step than what we've seen in 2015."