TIANJIN, China (MarketWatch) -- Current gold prices are too high to sustain, and high prices will also hamper investment abroad, an executive of China's largest gold producer by output, Zijin Mining Group Co. , said Sunday.

"The gold prices currently are unreasonable," Lan Fusheng, vice chairman of Zijin Mining, said in an interview with Dow Jones Newswires.

"Prices have been boosted not only by people's needs to hedge risks, but also by speculations," he said, adding that he thinks it would be sustainable for gold prices to stay at $1,200-$1,300 per ounce in the next few years.

Gold prices closed at $1,765 per ounce Friday, up about 34% from the lowest level of $1,318 in January. Gold peaked at $1,890 per ounce in mid-August.

Lan said he isn't optimistic about next year's gold prices and global economic situation. If the European debt crisis remains, which is very likely, investors tend to turn to the U.S. dollar and gold prices will decline accordingly, he said.

"Rising gold price is good to company's profit, but it makes overseas investment more risky and much more expensive," said Lan. However, it doesn't mean that Zijin suspends seeking overseas investment opportunities, he said.

Last year, Zijin mining stopped an acquisition of Platmin Congo, a unit of Copperbelt Minerals that owns a 68% interest in the Deziwa copper-cobalt project and a 68% beneficial interest in the Ecaille C copper-cobalt project in the Democratic Republic of the Congo, due to the Congo government's rejection.

The DRC's copper belt is a really good asset and every miner wants to be involved in its exploration, including Zijin, said Lan.

Copper prices are also too high, although the prices have slumped to about $7,600/ton from the culmination of $10,190/ton in February, said Lan.

To boost its copper business, which accounted for about 30% of its total revenue last year, Zijin is establishing a copper smelter with an annual capacity of 200,000 tons in China. Last year, Zijin copper production was around 90,000 tons, Lan said