Mining giant BHP has warned that a new wave of protectionism, promoted by former US president Donald Trump, is a threat to global trade, highlighting that the world faces a range of consequential elections reshaping the policy landscape.

Chair Ken MacKenzie told investors at BHP’s annual general meeting in Brisbane that the world’s biggest mining company is facing challenging times ahead of a knife-edge vote in the US next week between Trump and vice president Kamala Harris.

“Over the past year, the world has experienced ongoing humanitarian crises in the Middle East, Ukraine and Sudan, threats to the continued expansion of global trade by a new wave of protectionism, and a range of consequential elections across the globe that are reshaping the policy landscape,” MacKenzie said.

“In our operations, we are also seeing the lagging effects of inflation, uneven recovery in China and supply side surpluses for some commodities which is contributing to price volatility,” he said.

Shareholders attending the meeting were confronted with protests against BHP’s Queensland coal mines outside the venue and proceedings inside were briefly interrupted by anti-coal activists.

The miner owns five metallurgical coal (used in steelmaking) mines in Queensland’s Bowen Basin and an open-cut thermal coal mine at Mt Arthur in NSW’s Hunter Valley.

The company will look to lobby the Queensland government on progressive coal royalties to attract more investment, BHP chief executive Mike Henry said after the AGM.

“The reality of the coal royalty scheme in Queensland right now is it does not make investments and growth here attractive for us relative to the options we have in Chile, elsewhere to some of the other states in Australia, Canada and so on,” he said.

Queensland’s progressive coal royalty tiers were legislated by the former Labor government and have been committed to by the new Liberal National Party government over the four-year forward estimates.