China claims a minor island in the South Pacific, which is also claimed by Taiwan and Vietnam. Triton Island is the westernmost island of the Paracel Islands, located close to Vietnam. Since the 1970s, China has occupied the island regardless of the dispute over its possession.

Beijing has been quietly transforming reefs in the South China Sea into islands for years, adding military installations and assets such as missiles, radar systems, and airstrips. The United States has sanctioned the Chinese entities that helped Beijing build artificial islands and militarize them, according to Yahoo News. In many cases where islands did not exist in the sea, China has taken it upon itself to create new islands from scratch.

According to Kitsch Liao, assistant director of the Atlantic Council’s Global China Hub, Beijing’s increasingly aggressive and coercive behavior in the region over the past few months makes the buildup on the islands particularly worrisome. The buildup on the islands could provide China with key logistics that could aid it in projecting force in the region.

Woody Island, China’s largest military facility in the Paracel Islands, already has a population of approximately 1,000 people, an airfield, combat aircraft hangars, and HQ-9 surface-to-air missile batteries. According to satellite images captured this month and shared with The Daily Beast, it is now evident that China has begun constructing what appears to be an airstrip on a disputed island in the South China Sea.

The Daily Beast analyzed a satellite image captured by Planet Labs PBC on August 10 that reveals new construction on Triton Island. Compared to a Planet Labs PBC satellite image of the same island in March, Beijing has been busy expanding the island, which, according to maps, measures approximately 1 mile by several thousand feet.

According to The Drive, which first reported on the development, construction of the aerodrome on Triton Island has begun in recent weeks. According to an Associated Press analysis, the airstrip is likely longer than 600 meters or about 2,000 feet, allowing it to accommodate turboprop aircraft and unmanned aerial vehicles.

Yahoo News noted:

The airstrip is the latest indication that Beijing is continuing to militarize islands as part of a broader strategy to expand China’s presence in the South China Sea. Just last year, China had fully militarized three islands in the South China Sea, in a move that the Pentagon assessed was aimed at destabilizing the region and allowing China to extend its offensive capabilities beyond its own shores, by flying fighters, bombers, and more.

It is believed that China’s use of the islands pertains to Vietnam, and that the nature of the islands indicates reconnaissance and the onset of a conflict.

“The main target of Triton Island is Vietnam, not Taiwan,” Kitsch Liao, assistant director of the Atlantic Council’s Global China Hub told The Daily Beast. “This is [the] Chinese grand strategy in the SCS. From the preliminary assessment, the build-up on Triton Island may be a secondary base in the Paracel Islands [which could] function as [an] auxiliary base for the main base on the Woody Island.”

“The Great Walls of SCS have been built on sand, which are vulnerable during the war because they are not defensible,” Si-fu Ou, of Taiwan’s Institute for National Defense and Security Research said. “In peacetime, however, the man-made islands are quite useful to conduct a variety of the missions, for instance, presence, ISR (intelligence, surveillance, and reconnaissance), situation awareness, and gray zone-tactics.”

Brad Martin, a retired U.S. Navy officer and senior policy researcher at RAND, told The Daily Beast that the Triton Island expansion may also be an attempt to make it more difficult for China’s adversaries to successfully counteract a potential move to seize Taiwan.

“It’s just a way of multiplying places to put things. And in addition, the more places they have to put things, if a war should occur, the more places they can go, the more places the United States and its partners, and allies have to target. And that creates a resource drain for the force. It will be trying to defend Taiwan,” said Martin, who previously served as an operations analyst at the Pentagon’s Office of the Chief of Naval Operations. “The more lily pads there are, the more places there are to play Whac-A-Mole, the harder it is for the opposing force to deal with it.”

China has previously asserted that its island construction is solely defensive. However, its construction on islands overlaps with the territorial interests of Brunei, Malaysia, Taiwan, Vietnam, and the Philippines, as well as international trade routes. Yahoo reports that China’s Coast Guard has had several incidents with the Philippines in the Spratly Islands this year.

China’s denial of the apparent initiative has prompted the United States to dispatch ships close to the contested islands. As in previous years, a U.S. guided-missile destroyer will undertake “freedom of navigation operations” (FONOPs) at least twice this year near the Paracel and Spratly Islands to prove its point.