Cambodia and China denied reports on Tuesday that they are building a "secret naval facility" for the Chinese fleet.

Citing unnamed Western officials, The Washington Post reported that a new facility was being built for the "exclusive" use of the Chinese navy at Cambodia's Ream base (which is located on the Gulf of Thailand).

The base is troubling for Washington, as the US has long had "suspicions" that the base was being secretly converted for use by China.

Australia's new Prime Minister Anthony Albanese labeled these reports "concerning", saying he encourages China to be "transparent about its intent and to ensure that its activities support regional security and stability."

Cambodia's Deputy Prime Minister, Prak Sokhonn, rejected the report, describing them as "groundless accusations", in a call with Canberra's FM Penny Wong, according to a statement by Phnom Penh. 

A Spokesperson for the Cambodian government had earlier told AFP that the base was not a secret. "Cambodia won't allow the Chinese military to use it exclusively or to develop the site as its military base," spokesperson Phay Siphan said.

China's Ambassador to Cambodia and Phnom Penh's Defense Minister will attend a ground-breaking ceremony on Wednesday for new facilities at the base.

Beijing and Canberra have both voiced concerns over each other's influence in the region, with Australia voicing concern with China's security pact with the Solomon Islands, and China voicing concerns with regards to the AUKUS security alliance, which was established with China in mind, not to mention the US' increasing weapon shipments to Taiwan.