Rio Tinto plans to start exporting from the $6.2 billion Oyu Tolgoi copper mine in Mongolia on Friday, according to an invitation received by Reuters.

Journalists have been invited to attend a ceremony at the mine on June 14 to mark the first shipment.

Rio Tinto, operator of the mine, declined to comment on the event. Its subsidiary Turquoise Hill Resources Ltd owns a 66 percent stake in the mine, with the Mongolian government owning the remainder.

Rio has been producing at the mine for several months, and has been aiming to start exporting by the end of June. But it has said since February it would not start shipping until it resolved a range of disputes with the Mongolian government.