The world needs more mines to cope with rising demand for key energy-transition metals like copper, as mergers and acquisitions will not plug a looming supply gap, Rio Tinto Group Chairman Dominic Barton said.

Uranium Energy (NYSE:UEC) +2.3% pre-market Monday after saying it agreed to acquire Rio Tinto's (RIO) uranium production assets in Wyoming, including its fully-licensed Sweetwater plant and a portfolio of mining projects,

Rio Tinto’s Wyoming assets contain resources estimated at 175 million pounds (mlb) of triuranium octoxide (U3O8).

NYSE American-listed Uranium Energy Corp (UEC) announced on Monday its acquisition of Rio Tinto's Wyoming assets, which include the Sweetwater plant and a portfolio of mining projects, for $175-million.