Mining giant Rio Tinto plans to cut around 170 jobs at its Pilbara operations in Western Australia over the next few months, unions have been told.

The Western Mineworkers Alliance (WMWA), which represents workers at Rio’s Pilbara operations, says it had been informed about the proposed job losses, and was in talks with Rio’s management on the best way to handle them.

“Job cuts are never good news. However, given the current industry climate, the news is unfortunately not surprising,” union representative Stephen Price said in a statement.

“Through our discussions with Rio we understand that most of the job losses will come from support roles.”

The WMWA expects about 300 roles will also be cut from Rio’s Perth offices, but no details have been announced yet.

Rio Tinto was not immediately available for comment.

The news follows weeks of media speculation about the extent of job cuts in Rio’s WA operations, as the world’s second largest iron ore miner hunts for cost cuts amid a prolonged sector downturn that forced it into an $US866 million loss in 2015.

The company had been expected to cut up to 700 jobs at its profitable WA iron ore unit, on top of nearly 800 cuts last year.

It slashed global employee numbers more than eight per cent to 54,938 in 2015.

Rio told employees in January there would be no pay increases in 2016, in view of the tough year ahead.

It also asked employees to limit their travel, and flagged further scrutiny over consultancy and contractor spending.