A group of shareholders, who say they represented interests with more than US$3.5 trillion under management, put forward a resolution on public policy advocacy on climate change and energy by relevant industry associations.
The resolution proposed that Rio listed all payments made to industry groups, evaluate whether advocacy positions taken by those groups served the company's financial and energy policy interests, and evaluate whether those positions were consistent with Rio's pledge of support for the Paris Agreement.
Speaking to the AGM, a representative of the shareholder group said Rio had resisted the requests in the resolution and there was a misalignment of interests between Rio and industry associations.
Rio chairman Simon Thompson said the board supported the substance of the resolution.
"You say we have ignored the substance of the resolution and that's simply untrue," he said.
"It disregards the huge progress Rio Tinto has made on climate change."
Thompson said the company had reduced emissions by 38% since 2008 and recently exited the coal sector, though he admitted that was primarily a value decision.
He said some of Rio's main metals produced - copper, aluminium and boron - were essential to human progress and the transition to a low-carbon economy.
"The mining industry has to be part of the solution to climate change - and we are determined to be part of the solution," Thompson said.
Thompson said Rio was a member of hundreds of industry groups across the globe, and climate change wasn't the only issue to take into consideration.
"It is only one of about 12 major areas we engage with the Minerals Council of Australia," he said.
Thompson admitted there was misalignment between Rio and the MCA on climate and energy policy.
"[Climate change] is going to be one of the defining issues for the world, and the mining industry of course," he said.
"We believe the way to solve this issue is through engagement."
The voting results on the resolution were not yet available at the time of publication.
Rio shares rose by 0.9% to A$80.42.