Indonesia holds the world's largest nickel reserves and uses those reserves to attract investment in the battery supply chain. 

Tesla has existing supply contracts with Vale to supply nickel from the Brazilian miner's Canadian mines and this year signed an agreement with Talon Metals for 75,000 tonnes a year from the Tamarack nickel project in Minnesota, US. 

Nickel contracts are also in place with BHP in Australia, Chinese refiners and a project in the French territory of New Caledonia. 

Tesla is diversifying its direct supply of key battery metals cobalt, lithium, and nickel and sees strong demand for these critical minerals going forward. 

Tesla has also been linked to building a vehicle manufacturing plant in Indonesia after negotiations with the Indian government struggled to make headway. 

A consortium led by South Korea's LG Energy Solution, the world's second-largest maker of electric vehicle batteries, last month said it planned to invest US$9 billion in Indonesia as part of a deal that would include nickel refining to producing battery cells in Indonesia. 

LG's larger rival, China-based Contemporary Amperex Technology, which is already a supplier to Tesla, entered a similar-sized deal with Jakarta in April this year. 

Musk this month said he did not rule out buying a mine to ensure Tesla was supplied with key battery metals. 

Widodo, who has asked Musk to build a space launch facility in Indonesia, said he had invited Musk to visit the country.