Five years of care required on China, says Rudd: AAP

Speak softly and carry a big stick.

That's the advice of former prime minister Kevin Rudd on how to handle an increasingly aggressive China in the Indo-Pacific.

Mr Rudd says a failure to adequately handle the diplomatic relationship between Canberra and Beijing within the next five years could lead to conflict by the end of the decade or in the 2030s.

Delivering ANU's 2022 JG Crawford Oration, Australia's 26th prime minister says China is on track to have its military ready to take Taiwan by force in the late 2020s or 2030s.

More: Kevin Rudd warns Australia could face war with China in the next five years