Indian energy giant Adani has ramped up the pressure on the Turnbull government to use taxpayers' money to deliver a $1 billion concessional loan for its controversial Carmichael mine with the company saying it would "review its options" if it missed out on the funding.

After more than seven years being held up in the courts and awaiting state and federal approvals, Adani chairman Gautam Adani said the board had made the final investment decision to proceed with the $16.5 billion mine in central Queensland.