Two of the smelters, operated by PT Smelter Nickel Indonesia and PT Cahaya Modern Metal Industri, were now completed and had gone through production trials, Ridwan Djamaluddin, director general of mineral and coal at the energy ministry, said.

Production trials at PT Smelter Nickel Indonesia's smelter, however, had been suspended as it was waiting for funds to continue operations, the statement said.

The third smelter, operated by state miner PT Aneka Tambang Tbk (Antam), is 97.7% completed, Ridwan said, but was not operational yet due to electricity supply issues.

"An auction (for electricity supply) has been held," he said.

In a bid to become a global hub for electric vehicle production, Indonesia is aiming to ramp up processing of its rich supplies of nickel laterite ore used in lithium batteries.

(Reporting by Bernadette Christina Munthe; Writing by Fathin Ungku; Editing by Ed Davies)