Rio Tinto CEO Tom Albanese said "resource nationalism" may curb supplies, with governments seeking to increase their share of mining profits.
Albanese said the approach may spread as governments around the world seek to boost their share of mining profits, potentially constraining supply.
Australia last week revised its mining tax after global mining communities led a campaign against it's introduction.
China also plans to extend a tax on oil, gas and coal output to the entire nation, after introducing the levy in Xinjiang province last month.
Albanese added the tax might not necessarily suit a developing country, reports Bloomberg.
The mining giant is considering an expansion to 300 million tons by 2015 from 220 million tons at its operations in Western Australia's Pilbara region.