The Rio Tinto chairman has resigned after mounting shareholder pressure over the mining giant destroying sacred Indigenous caves last year in Western Australia.

In a statement to the Australian Stock Exchange on Wednesday, chair Simon Thompson announced he would step down from the board and not seek re-election at the next annual general meeting.

Mr Thompson said the destruction of the Juukan Gorge caves in the Pilbara had "overshadowed" the successes of the miner, with the decision to destroy areas of cultural importance to local Aboriginal groups a major failing of his.

"These successes were overshadowed by the destruction of the Juukan Gorge rock shelters at the Brockman 4 operations in Australia and, as chairman, I am ultimately accountable for the failings that led to this tragic event," Mr Thompson said in statement.

"Throughout my seven years on the Rio Tinto board, I have endeavoured to promote a progressive environmental, social and governance agenda.

"While I am pleased with the progress we have made in many areas, the tragic events at Juukan Gorge are a source of personal sadness and deep regret, as well as being a clear breach of our values as a company."

Directors Sam Laidlaw and Simon Mckeon will become joint chairs of Rio Tinto.

Originally published as Rio Tinto chair quits after caves destroyed