China may be constructing an airstrip on a disputed island in the South China Sea that is also claimed by Vietnam and Taiwan, satellite images suggest.
Pictures of Triton Island, one of the islands in the Paracel group, appear to show the construction of a runway more than 600 metres (2,000ft) long, according to analysis by Associated Press. This would be long enough to accommodate turboprop aircraft and drones but not fighter jets or bombers.
China claims almost all of the South China Sea, despite an international tribunal finding its arguments to be without legal basis.
Beijing has previously asserted its claims in the waters by building and fortifying islands elsewhere, including constructing military facilities on the Spratly group, further to the east. Any work at Triton Island appears to be in its early stages.
The South China Sea, a strategically important waterway and one of the world’s busiest trading routes, is highly disputed and considered a potential flashpoint.
Countries including Taiwan, Vietnam, the Philippines, Malaysia and Brunei have overlapping claims, while the US considers the waters crucial to its national interests and often carries out “freedom of navigation operations”.
Images of Triton captured by Planet Labs show vehicle tracks and what appear to be containers and construction equipment. The island, the southern- and western-most in the Paracel group, is roughly equidistant from the coast of Vietnam and China’s island province of Hainan. It has been controlled by China since 1974.
Triton already contained small harbours and a helipad, according to the Asia Maritime Transparency Initiative, part of Washington’s Center for Strategic and International Studies. A star from the Chinese flag, and a hammer and sickle representing the ruling Communist party, are featured in two fields and can be seen in satellite images.
China has not provided details of its island construction projects and maintains any work is designed to improve navigational safety. It has rejected accusations that it is militarising the waterway.
Tensions over the sea have increased in recent months, with another of the key claimants in the dispute, the Philippines, accusing China of using vessels in dangerous and aggressive ways, including firing water cannon and a military-grade laser at its coastguard boats.
In March, the Philippines expanded US access to its military bases, enhancing Washington’s footprint in the region. The Philippines has also strengthened military ties with Japan and Australia, two US allies.
Hunter Marston, a researcher and analyst at the Australian National University, in Canberra, said some officials in Hanoi appeared to perceive the developments on Triton Island with relative ambivalence and did not consider the islands to be “an existential threat to Vietnam’s security”.
However, the reports were likely to be perceived in different terms by the public, which “is very alert to these developments and very anti-China, especially in regard to the East Sea,” he said, referring to Vietnam’s name for the sea.
Joe Biden said this month that he planned to visit Vietnam soon, adding that the country wanted to upgrade its relations with the US.
Marston said any improvement in relations would be Vietnam’s way of signalling to China that it had “a diverse network of security and strategic partners, and that trust is growing with Washington”.
It appeared, however, that China’s president, Xi Jinping, could be travelling to Hanoi shortly before Biden, he added, citing an unconfirmed report. This would probably reassure Beijing that “China comes first”.
