The Nobel laureate who spent much of her life fighting for her people's freedom failed in a long-awaited speech on Tuesday to offer any solution to end savagery in Rakhine State.

Suu Kyi, now Myanmar's de facto leader, defended the country's security forces which according to irrefutable evidence have committed extra-judicial killings, the slaughter of children, rapes and the torching of villages.

The United Nations' chief Antonio Guterres warned before the speech that unless she acted now "the tragedy will be absolutely horrible".

World leaders are scheduled to discuss the crisis at the UN General Assembly in New York on Wednesday.

It is time for Australia to step up to engage other countries to help solve a crisis has the potential to spiral out of control and destabilise the region.

Aid agencies say by the end of the year close to one million mostly Rohingya Muslim refugees could be living in squalid Bangladesh border camps.

If they cannot return to Rakhine many are expected to take to boats, generating a fresh wave of refugees trying to reach Australia, Thailand, Malaysia and Indonesia.

Myanmar's persecution of Rohingya in its poorest state has also radicalised a new generation of Muslims at a time of growing concern about the spread of Islamic extremism across south-east Asia.

Islamic State militants from the Middle East have been fighting in a four-month siege in the southern Philippine city of Marawi and al-Qaeda last week called for jihadists worldwide to "help" the Rohingya.

The crisis has also divided the Association of South-East Asian Nations, of which Myanmar is one of 10 members, as the treatment of Rohingya stokes tensions in predominantly Muslim countries such as Indonesia and Malaysia.

Foreign Minister Julie Bishop, who is in New York, should take the lead in forming a multinational coalition to respond to the worst humanitarian crisis in Asia in decades.

Australia should dramatically increase its aid to distressed Rohingya and consider deploying Australian Defence Force assets, like amphibious ships to deliver it.

Sanctions lifted when Myanmar started to implement reforms and open to the world in 2011 after half a century of brutal military rule should be re-imposed.

Australia should also end its defence training and support for Myanmar's military, sending a message to its generals that the Rakhine atrocities are unacceptable in a civilised world.