Work on the Oyu Tolgoi underground project, in Mongolia, has been slowed as a result of measures put in place by Mongolia to contain the spread of Covid-19, diversified mining major Rio Tinto said on Monday.

Mongolia has restricted the movement of goods and people in the country, as well as cross-border travel.

Rio Tinto said that these measures would impact on the availability of specialist service providers at the site, which were required to safely continue work on technical activities, such as the headframe commissioning of Shafts 3 and 4.

The measures put in place by Mongolia had “inevitably resulted in a restriction on the movement of goods and people in the country and this is slowing down construction activity at the underground project”, said Rio Tinto copper and diamonds chief Arnaud Soirat.

“It is too early to determine the impact of this and the team is doing all they can to minimise the disruption in a challenging environment. We will continue to work with our suppliers, customers and the government."

The mine design for the underground project remains on track to be completed in the first half of this year, with a definitive estimate to be provided for the development of the orebody in the second half of 2020.

Despite the impact of Covid-19, the openpit of the Oyu Tolgoi mine continues to operate and deliver shipments of copper concentrate to its customers.

Countries around the world are stepping up efforts to contain the spread of the virus, which has killed about 6 300 people with nearly 170 000 infected globally. The World Health Organization has declared Covid-19 a pandemic.

The Oyu Tolgoi mine is owned by the government of Mongolia (34%) and Canada's Turquoise Hill (66%, of which Rio Tinto owns 51%). Rio Tinto is the operator of the project.

The underground mine is expected to produce more than 500 000 t/y of copper, compared with current openpit production of 175 000 t/y to 200 000 t/y.