The prime minister will use a speech to the National Press Club in Canberra on Wednesday to lay out areas of practical action the federal government can take to deal with emergencies.

Mr Morrison says he does not want to take over police, fire, ambulance and medical services from the states.

"State fire services have performed with incredible skill and bravery this fire season, saving many lives and homes," he will say.

"(But) where, when and how the resources and capabilities of the federal government should be engaged is less clear."

He says the bushfires have tested the limits of how the federal government interacts with the states, which in the past has required a request for assistance from premiers.

In order to clear up issues such as when defence forces can be used, the government will examine three steps:

* Constitutional and legal change allowing the declaration of a national state of emergency and the Commonwealth to take action on its own initiative, including the deployment of the ADF;

* examining the legal interface with the states and territories on responsibilities when it comes to preparation for, and response to, natural disasters and emergencies of national scale;

* an enhanced 'national accountability' for natural disaster risk management, resilience and preparedness, including setting targets, reporting on key actions and national standards.

The defence force involvement in supporting bushfire efforts was bolstered within a few weeks from 900 personnel in December to over 6500 in January, with the federal government acting without a request from the states but with the approval of Governor-General David Hurley.

It was the largest domestic ADF operation in Australia's history, with more than 13 fixed wing aircraft, 20 rotary wing platforms and three naval vessels involved.

Mr Morrison will also repeat his support for a royal commission, which - if backed by the premiers and chief ministers - will have the initial task of auditing previous inquiry recommendations.

Federal parliament will resume next week with a day of reflection on the bushfires scheduled for February 4.

Australian Associated Press