More than half of the 450 workers at BHP's bulk export terminal in Western Australia's Port Hedland are expected to walk off the job for eight hours on Thursday afternoon.
Premier Roger Cook conceded the action was concerning and called for the mining giant and unions to return to the bargaining table.
"I don't believe it will be a common occurrence," he said.
"I'm encouraging all parties to continue to negotiate and come to a good outcome."
The planned strike is the first major industrial action to hit the resource-rich Pilbara region in decades and unions estimate it could cost BHP $50 million in lost revenue and the state $6.8 million in royalties.
But Mr Cook said he didn't think the historic industrial action would impact future investment in the Pilbara region and the state's broader resources sector.
"People respect that this is part of our industrial relations system," he said.
"There's always been negotiations between unions and the mining companies in the northwest.
"We continue to see very strong investment in the Pilbara from our resources industry and we'll continue to see it into the future."
WA Nationals Leader Shane Love said unions were growing more powerful in the state and exerting influence over the ruling Labor party.
The mining giant and combined ports unions failed to reach a wage agreement following a five-hour bargaining session earlier in the week.
BHP previously said plans were in place to continue operations.
The Electrical Trades Union, the Western Mine Workers' Alliance (Australian Workers Union) and the Australian Manufacturing Workers' Union are involved in the industrial action.
They have called for an eight-hour work stoppage, to run from 2pm to 10pm local time, saying BHP had failed to progress wage-bargaining talks for more than six months.
Earlier on Thursday, Electrical Trades Union members rallied outside BHP offices in Melbourne and Brisbane in solidarity with their WA counterparts.
BHP has expressed disappointment that the unions had decided to proceed with the strike following progress made during negotiations on Tuesday.
The miner said there had been eight bargaining sessions and it had offered a 16 per cent pay increase over four years for most workers, and improved allowances.
Bargaining for BHP's port operations agreement started in October 2025.
About 577 million metric tonnes were exported from Port Hedland in 2024/25, worth an estimated $115.8 billion.
The company said it paid $2.8 billion in state royalties and related government payments in the 2025 financial year, contributing about nine per cent of all WA government revenue.
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