Hun Sen, who is on a three-day visit to Vietnam, insisted at a news briefing with his Vietnamese counterpart, Nguyen Xuan Phuc, that the Cambodian Constitution does not permit foreign military bases.
"I want to emphasize to you that the Constitution of the Kingdom of Cambodia does not allow any country to set up military bases in Cambodia," Hun Sun said through a translator.
Asia Times reported last month that China has lobbied Cambodia since 2017 for a base in the southwestern province of Koh Kong in the Gulf of Thailand.
Hun Sen dismissed the report.
"There has been distorting information over the past month that there are preparations to build military establishments in Cambodia," he said. "I want to say and I have just told Prime Minister Nguyen Xuan Phuc and the Vietnamese delegation that this is fake news and there's no such thing happening in Cambodia."
Asia Times said the alleged naval base is part of a $3.8 billion tourism development named Dara Sakor Beachside Resort led by a Chinese company. It said the project reportedly includes a deep-water port, an international airport and manufacturing facilities.
It is located in the Gulf of Thailand but has direct access to the South China Sea, most of which is claimed by China. China in recent years has built seven artificial islands in the disputed Spratly Island chain and placed military equipment on some of them, raising alarm among other countries in the region and in the United States.