PHNOM PENH (AP): The top US Army officer for the Asia-Pacific region was in Cambodia on Monday in the latest visit by US officials aimed at improving estranged ties between the two nations and their militaries.

The two-day visit by a delegation led by Gen Ronald P Clark, commanding general of the United States Army Pacific, comes against a background of rocky relations with Cambodia, whose government Washington has long criticized for political repression and human rights violations.

There is also particular concern about its close ties with China. The United States and others fear that China's navy may have been given exclusive access to a base at Ream on the Gulf of Thailand, which would allow it to more easily project its power from the South China Sea to the Indian Ocean.

China is Cambodia's most important ally and benefactor, with a strong influence on its economy.

A Cambodian army press release said the country's military chief Gen. Mao Sophan in his meeting with Clark discussed cooperation in defence, trade, tourism, culture, counterterrorism, peacekeeping and demining as well as the recovery of missing American military personnel during the Vietnam War.

The two also discussed the possible resumption of the joint Angkor Sentinel military exercises, last held in 2016.

A statement issued by Prime Minister Hun Manet said the US general expressed his interest and appreciation for Cambodia sending UN peacekeepers to several countries around the world.

Hun Manet thanked the US government for supporting Cambodia in clearing unexploded ordnance. Decades of war that ended in the late 1990s left 4 million to 6 million land mines and other unexploded munitions, including US bombs.