Saefulhak said he expects miners of low grade nickel ore, however, to lower their production this year as the country stopped ore exports at the start of 2020. Most local smelters prefer higher grade nickel ore.

"They (miners) will put a break on low grade ore production," he said, although he expects low grade nickel ore output will be ramped up again once battery chemical plants currently on the planning board start their operations.

Chinese battery firm GEM Co Ltd expects to start trial production at its Indonesian nickel and cobalt plant in August, its president said in November, with the first phase of operations up and running by the end of 2020.

Saefulhak said there are at least four such plants to extract chemicals for use in batteries for electric vehicles.

Indonesian government is keen to take advantage of the country's nickel deposits and is aiming to create downstream industries for the mineral, eventually aiming for the domestic production of electric vehicles.

Indonesia also produced 1.1 million tonnes of ferronickel last year, nearly twice the 573,000 tonnes a year earlier. Output of nickel pig iron also doubled to 692,429 tonnes in 2019, up from 323,000 tonnes in 2018, ministry data showed.

The country also produced 65,000 tonnes of nickel matte last year, down from 75,000 tonnes a year before.

Indonesia exported 30.2 million tonnes of nickel ore last year, up from 20.1 million tonnes in 2018, Saefulhak said.

Indonesia's statistics agency put the country's 2019 nickel ore exports at 32.3 million tonnes.

(Reporting by Wilda Asmarini; Writing by Fransiska Nangoy; Editing by Tom Hogue)