Mongolia eyes 50% stake in key Oyu Tolgoi project
Mongolia is seeking greater control of one the biggest mining projects in the country, which is being developed by Rio Tinto and Ivanhoe Mines.
The government said it wants to raise its stake in the Oyu Tolgoi project to 50% from 34%.
According to the original contract signed in 2009, Mongolia can increase its stake only after 30 years.
When completed, the project is expected to account for as much as 5% of Mongolia's gross domestic product.
"At this moment the government has made the decision that we will send the proposal to renegotiate the timeframe with which to increase the Mongolian portion to 50%", Dashdorj Zorigt, Mongolia's mining minister said.
The project, developing what is expected to be one of the world's biggest copper mines, has seen huge investment being made by Rio Tinto and Ivanhoe Mines.
Analysts believe the companies are likely to raise objections to the government's proposal.
"They developed a project based on a certain economic framework which is now going to change," Gavin Wendt of Mine Life told the BBC.
"The consequences of this will be significant," he added.
Cameron McRae of Rio Tinto said while the company was willing to hold talks with the Mongolian government, it expected the current term and conditions to be honoured.
"What we are demonstrating is that the investment agreement is a contract, and we are going to honour our commitment and expect the government to honour its commitments," he said.
However, analysts warned that it will be a tricky situation for the mining companies.
"They don't want to jeopardise their existing investment by upsetting the government," Mine Life's Mr Wendt said.
Analysts said the Mongolian government's decision was not a surprising one, given that countries were looking to have a bigger control over their natural resources.
"There is a worldwide trend over the last 12 months of growing resource nationalism," said Mr Wendt.
Jonathan Barratt of Commodity Broking added that authorities were doing this to ensure that a greater share of profits from the country's resources passed into the economy.
"You can either tax them [the mining companies] on royalties or you can become their partner," Mr Barratt said.
However analysts said the government's move could backfire if companies become wary of investing in the country.
"It is concerning not only for Rio and Ivanhoe, but also for all of the major companies that are establishing mines in Mongolia," Mine Life's Mr Wendt said.
"It's going to add to uncertainty, to costs of developing projects and companies don't like that."