BHP on Tuesday reported an underlying attributable profit of $US6.6 billion ($A9.6 billion) for the six months to December 31, down almost a third (32 per cent) from a year earlier.
Profit from operations in the half fell more than a quarter (27 per cent) to $US10.8b ($A15.6b) on lower prices for iron ore and copper, higher royalties paid on coal in Queensland and inflation.
But this was offset by record iron ore production and higher prices for coal and nickel.
Earnings before interest, taxes, depreciation and amortisation (EBITDA) was $US13.2b ($A19.1b), down 28 per cent.
Net operating cash flow was $US6.8b ($A9.8b), down 41 per cent.
"Significant wet weather in our coal assets impacted production and unit costs, as did challenges in securing sufficient labour," BHP Chief Executive Mike Henry said.
"We are positive about the demand outlook in the second half of FY23 and into FY24, with strengthening activity in China on the back of recent policy decisions the major driver."
He said inventory movements during the half contributed to costs, including the planned draw-down at Olympic Dam after inventory built up during the smelter refurbishment last year.Â
"We expect these factors to abate in the second half and for unit costs to fall, in line with revised guidance," Mr Henry said.
In Western Australia, BHP is planning to lift iron ore production to 330 million tonnes per year, supported by its status as the lowest cost major iron ore producer globally.
"We are seeing ongoing positive exploration results from Oak Dam, which provides growth potential for our copper business in South Australia," Mr Henry said.
BHP reported it was on track to meet its 2030 target on operational greenhouse emissions.
Capital expenditure on operational decarbonisation is expected to be around $US4b ($A5.8b) up to the 2030 financial year to align with 2030 and 2050 targets and maximise shareholder value, BHP said.
The acquisition of OZ Minerals is on track to be implemented by early May.
The global miner declared a fully franked interim dividend of US 90 cents a share, down 40 per cent from last year's record return to shareholders.