Rio Tinto has flagged job losses at its coal and aluminium operations, after announcing plans to cut spending and make savings worth billions of dollars.

"We're going to have some difficult discussions with labour," Rio Tinto chief financial officer Guy Elliott told an investors' briefing on Thursday.

He said coal and aluminium would be the focus of cost cutting as the organisation aimed to reduce its operating costs by more than $US5 billion ($A4.81 billion) by the end of 2014.

"Coal and aluminum will be the focus, but actually nobody is immune.

"We are absolutely looking everywhere. We're looking at 100 per cent of our costs to try and improve them and that means in offices, in operations, it means in smelters, it means in mines, it means everywhere."

Rio Tinto chief executive Tom Albanese said operations would not shut just to meet cost-reduction targets.

"We're going to shut down operations, if they don't deliver cash flow.

"Those are independent actions."