Speaking to local media at Randgold's Tongon gold mine, Bristow said Côte d'Ivoire had all the ingredients for the development of a world-class mining industry but to achieve this, the government and mining sector needed to work together in "a committed, long-term partnership".

He said Tongon alone had paid almost US$1 billion to the state and local suppliers and contractors but power supply from the national grid remained challenging and the company had not received any indication of when and how the state-owned electricity company would reimburse Tongon for its $28 million investment in the grid's expansion.

"Côte d'Ivoire needs more Tongons and that means more investment by the mining sector as well as by the government," Bristow said.

"Issues that should be addressed immediately are the increasingly serious problem of illegal gold mining, the granting of permits to companies that lack exploration capacity and expertise and a history of delivering world class mines, and the acceleration of the permitting process."

Earlier this month in the DRC, Bristow said the Kibali gold mine's underground operations were reaching final commissioning and Kibali should be preparing to pay back loans - but he was concerned this would be impeded by the increasing amount of debt owed to the mine by the government, which was currently more than $200 million.

He was also concerned by the DRC's recent re-introduction to parliament of a new mining code which he said was "exactly the same" as the one withdrawn in 2015 after it was deemed it could destroy the Congolese mining industry.

However Bristow had said he was confident a "fully committed partnership" between the DRC and mining companies was within reach and said the company continued to invest in the DRC despite all the challenges, including a volatile political climate and deteriorating economy.

Randgold's half-year profit was up 53% on the previous corresponding period to $187.7 million.