China will hold its first-ever exercise with Cambodia's navy next week, in swift succession to a visit by the military vessels of Beijing's old enemy Japan, the latest sign of China's growing presence in a region where maritime tension is rising.

Three warships carrying 737 Chinese sailors will dock on Monday at a port in Preah Sihanouk province, just over a day after the scheduled departure of three vessels of the Maritime Self-Defense Force now holding cultural exchanges with Cambodian navy personnel.

While attention focuses on China's activities in the East and South China Seas, Beijing has been busy strengthening defense and economic ties with Cambodia, from which it is increasing receiving political support, particularly within the Association of South East Asian Nations (ASEAN) grouping.