Musk and the Mongolian government talked about a potential joint research venture on the use of rare earth elements and battery minerals, the statement added.

Resource-rich Mongolia is endowed with extensive deposits of rare earth minerals and copper, which are critical materials in the electric vehicle supply chain.

The country recently commenced production at the Oyu Tolgoi mine, one of the world's largest known copper and gold deposits, which is slated to eventually produce more than 500,000 metric tons of copper a year.

(Reporting by Andrew Hayley; Editing by Jamie Freed)

By Andrew Hayley