Eighty percent of the Oyu Tolgoi deposit's total reserves lie deep underground. As of today, the construction of the underground mine is at over 60 percent and is planned to be commissioned in 2023. Currently, the underground mine is under lateral development phase, excavating 1,800 meters per day. A primary stone crushing section is also under construction at the depth of the mine and is 80 percent complete. Construction of the underground mine is likely to be delayed to some extent due to the inability of foreign experts to visit the country after the border-closure in prevention of the COVID-19 pandemic. Deputy Prime Minister U.Enkhtuvshin said that the State Emergency Commission would pay attention to resolving this issue.

In the first quarter of 2020, the Oyu Tolgoi deposit extracted a total of 35.2 thousand tons of copper and 26.2 thousand ounces of gold which means the amount of extracted copper and gold fell by 23 percent and 78 percent respectively. It was mainly due to a decrease in the copper content of the concentrate extracted from the open pit, reported CEO of Erdenes Oyu Tolgoi Ts.Tumentsogt.