BHP’s senior executive Tim Day has denied the iron ore sector is in decline in an indirect rebuke to rival Fortescue and its billionaire executive chairman Andrew Forrest, who has warned that China’s pivot towards lower emissions steel was threatening the industry.

Forrest has warned that Western Australia’s Pilbara region, often described as the economic engine room of the nation, would become “a wasteland” if its miners failed to adopt green technology to counter the lower grades of iron ore being extracted from its ageing pits.