He said the decline was attributable to the transition of production activities of PT Freeport from open mining to underground one, which, he estimates, could prolong for two years.
When the company returns to normal operation, Indonesia's gold production is likely to reach about 120 tons per year, he added.
The number of gold mining companies nationwide currently stands at 28. Therefore, even if Freeport cannot return to normal by the end of the year, he predicts the national gold production in 2020 is not too far from the 100 tonne figure.
Freeport is a US gold mining company with a total production of 80 tons per year, making it the largest contributor to Indonesia's gold production.