WASHINGTON - A US State Department spokesman on Monday (July 22) said it was concerned after reports of a secret deal that allows Chinese armed forces at a Cambodia naval base.

The US is "concerned about media reports that there is a secret agreement detailing a military arrangement between China and Cambodia", the spokesman said.

"The United States continues to promote the peace and prosperity of South-east Asia and the centrality of the Association of South-east Asian Nations (Asean).

"We are concerned that a possible Chinese military presence in Cambodia would both threaten regional stability and the position of Asean," the spokesman said.

"Further, we are concerned that this base could undermine the prospects for the peaceful settlement of disputes, the promotion of maritime safety and security, and the freedom of navigation and overflight. The United States seeks a constructive bilateral relationship with Cambodia that serves the interests of both the American and Cambodian peoples."

The Wall Street Journal on Monday reported that China has signed a secret agreement allowing its armed forces to use a Cambodian navy base near Sihanoukville, which would give China exclusive rights to part of a Cambodian naval installation on the Gulf of Thailand, not far from a large airport now being constructed by a Chinese company.

The report, quoting "US and allied officials familiar with the matter", said the agreement would allow China to use the base for 30 years, with automatic renewals every 10 years thereafter. China would be able to post military personnel, store weapons and berth warships there, the report said.

Cambodian Prime Minister Hun Sen swiftly rejected the report, denying any such agreement.

"This is the worst-ever, made-up news against Cambodia," he was quoted as saying. "No such thing could happen because hosting foreign military bases is against the Cambodian Constitution."

The Wall Street Journal, in its report itself, said Chinese and Cambodian officials had denied that there were plans for a Chinese military base in the country.

It quoted Mr Phay Siphan, a Cambodian government spokesman, calling it "fake news" and saying last Friday (July 19): "Nothing is happening like that."