A new runway being constructed in a Cambodian jungle has added to fears that China is preparing to base troops around the southeast Asian country.

The New York Times reported that the runway, being constructed by a Chinese firm at Dara Sakor International Airport near Cambodia’s southwestern coast, has a tight turning bay: a style often used by fighter jet pilots.

At 10,500 feet long it will be the longest runway in the country, and will be located near ports the US fears may also be used by Beijing’s troops.

Cambodia borders the Gulf of Thailand, which neighbours the South China Sea, where China has expanded its military presence in disputed territory over the past decade.

China, Vietnam, the Philippines, Taiwan, Malaysia and Brunei have competing and sometimes overlapping territorial claims in the South China Sea.

The US, which sends naval ships on ‘freedom of navigation’ patrols there, has become concerned by Beijing arming islets and reefs around the sea to bolster its sovereignty claims. Smaller Asian nations have accused Beijing of using bullying tactics in the region.