The dispute between the Mongolian government and Rio Tinto over repatriation of Oyu Tolgoi earnings continues to delay the first copper shipments out of the country.

The stalemate "could heighten investor concerns about the risks of mining in Mongolia and threaten Rio Tinto's plans to grow its copper portfolio to ease dependence on iron ore," Reuters reported Thursday.

Copper exports were scheduled for June 14, postponed till June 21, and now are being postponed again until the current dispute is settled.

Mongolian government officials have yet to budge on their demand to keep revenue from the giant copper and gold project in domestic banks.