Chinese Foreign Minister Wang Yi wrapped up a three-day official visit to Cambodia on Tuesday where he met with Prime Minister Hun Manet.
The two countries agreed to strengthen cooperation in areas such as defense and security.
Hun Manet praised China's "One Belt, One Road" initiative for creating a huge economic zone, saying it is contributing to Cambodia's development.
For his part, Wang stressed that China will always be Cambodia's most reliable friend and firmest supporter.
Wang's visit was the final stop on a three-nation tour that also took him to Indonesia and Papua New Guinea. Amid territorial disputes with the Philippines over the South China Sea, Beijing is seen to be bolstering ties with other countries in the Asia Pacific region.