Turnbull, the former prime minister of Australia, has been appointed as chairman of FFI subsidiary Australian Fortescue Future Industries (AFFI).

AFFI is one of 17 wholly owned subsidiaries being established for FFI operations around the world.

Warner, a former diplomat, intelligence official and public servant, has been appointed as FFI special advisor, international affairs.

FMG chairman Dr Andrew Forrest AO welcomed Warner and Turnbull to FFI.

"Mr Warner's expertise on global intelligence is incomparable, and his knowledge will be critical as we continue to engage foreign governments to explore green hydrogen opportunities," he said.

"Mr Turnbull has been involved in key policy decisions that have not only altered Australian society but also have international implications for other countries facing similar issues including the environmental conservation and energy crises.

"He will bring a level of vital experience as we continue our journey to bring FFI to a global audience."

Since leaving politics in 2018, Turnbull has been an advocate for the transition to renewable energy.

FMG has pledged to invest 10% of its annual net profit after tax in FFI.

FFI will assess opportunities in the global green energy space, including hydrogen.