Rio Tinto has signalled it's increasingly interested in lithium, with future demand expected to soar due to the take up of electric vehicles.
Dean Gehring, president and chief executive officer, was quoted in its in-house publication saying: "The Jadar project is strategically important for Rio Tinto Minerals and will complement our existing operations."
Gehring went on to describe it as "a very attractive investment" in the miner's portfolio.
Lithium is a small but essential component of rechargeable batteries that power mobile phones, laptops and even electric cars. It's been described by Goldman Sachs as the new petrol, but Rio's peers have proven less interested in the metal, which represents a relatively small slice of the market.
Rio recently committed another $20m (£13.9m) to the development of the Jadar lithium-borate project, taking its total investment to $70m. It's currently at the pre-feasibility stage, which involves economic, social and environment assessments.
"Where we are now, the focus is on building confidence in the various aspects of the project, in particular our orebody knowledge," Richard Storrie, general manager of Rio Tinto Serbia, said.