In a meeting with Cambodian Prime Minister Hun Sen on Tuesday, US Deputy Secretary of State Wendy Sherman focused on China's construction of new facilities at Ream Naval Base.

She sought clarification about the demolition of two US-funded buildings at Ream without notification or explanation, and “observed that a (Chinese) military base in Cambodia would undermine its sovereignty, threaten regional security, and negatively impact US-Cambodia relations,” according to the State Department.

In Beijing, Foreign Ministry spokesperson Wang Wenbin said China and Cambodia enjoyed a “traditional friendship” and were “comprehensive strategic and cooperative partners.”“The two sides have carried out fruitful cooperation in various fields, which has brought tangible benefits to the two peoples and made positive contributions to regional peace and stability," Wang told reporters at a daily briefing.

The State Department said Sherman urged Cambodia's leadership to maintain an independent and balanced foreign policy, “in the best interests of the Cambodian people.”Sherman raised the issue again during a visit to Thailand on Wednesday, saying that she had candid conversations with Hun Sen “about the direction the country is headed,” including China's presence at Ream and Cambodia's human rights and “anti-democratic record."

Ream faces the Gulf of Thailand that lies adjacent to the South China Sea, where China has aggressively asserted its claim to virtually the entire strategic waterway. The US has refused to recognise China''s sweeping claims, and the Navy's 7th Fleet routinely sails past Chinese-held islands in what it terms freedom of navigation operations.

China was the chief backer of the murderous regime of Pol Pot in Cambodia and has long maintained strong relations with Hun Sen, who has ruled for more than 30 years and grown increasingly repressive. Cambodia has also reliably blocked criticism of China within the 10-member Association of Southeast Asian Nations.