Cambodia and China broke ground on Wednesday on a Beijing-funded project to revamp a naval base that the US fears is intended for Chinese military use.
The Washington Post this week cited unnamed Western officials as saying the new facilities at Cambodia's Ream base - strategically located on the Gulf of Thailand -- were being built for the exclusive use of the Chinese navy.
Both countries deny the allegations, with Phnom Penh saying the base's development is not a secret, Cambodian defence minister Tea Banh and Chinese ambassador Wang Wentian were on hand Wednesday to see work begin on the new facilities, including a dry dock, slipway and sand dredging for larger ships to dock.
There was a lot of heavy construction machinery visible at the site.
It is not targeted at any third party and will be conducive to closer practical cooperation between the two militaries, better fulfillment of international obligations and provision of international public goods, Wang said.
The project, paid for with a Chinese grant, includes upgrading and expanding a hospital, as well as donations of military equipment and repair of eight Cambodian warships, according to Tea Banh.
There are allegations that the modernised Ream base will only be used by the Chinese military. The minister told several hundred people, including foreign diplomats, that it is not like that at all.
The Ream base is very small, don't worry too much. Another Cambodian official said that the revamp will be completed in two years.
Wang said it would deepen the iron-clad friendship between the two countries and modernise the Cambodian navy.
Washington suspects that the base is being converted for use by China as Beijing seeks to shore up its international influence with a network of military outposts, which has been a sore spot in US-Cambodia relations for years.
American embassy spokeswoman Stephanie Arzate said the United States and other countries in the region expressed concern about the lack of transparency on the intent, nature, and scope of the project, as well as China's role in its construction.
An exclusive PRC military presence at Ream could threaten Cambodia's autonomy and undermine regional security, Arzate told AFP.
Concerns about the base go back as far as 2019 when the Wall Street Journal reported on a secret draft deal that allowed Beijing to dock warships there.
Cambodia has since dismantled facilities at the base that were built partly with American money and played host to US military exercises.