Cambodian Foreign Minister Prak Sokhonn, along with ASEAN Aambassadors and Chinese Aambassador to Cambodia Bu Jianguo, jointly unveiled the three-storey building.
In his speech, Sokhonn said ARMAC will assist ASEAN member states and other interested countries to address the issues of landmines and the explosive remnants of war.
Initiated by Cambodian Prime Minister Hun Sen during the 21st ASEAN Summit in Phnom Penh in 2012, the building was fully refurbished with the support of the Chinese government.
Cambodia is one of the countries in the world that have been worst affected by landmines and unexploded ordinance. An estimated 4-6 million landmines and other munitions were left over from the war.
According to the government's figures, mines and explosive remnants have killed 19,723 people and injured or amputated 44,856 others in Cambodia between 1979 to 2015.
Foreign Minister Sokhonn, estimated Cambodia needs about US$338 million to entirely get rid of all types of mines and explosive war remnants in the next 10 years .