The federal government has deployed additional Australian Defence Force resources to support authorities in fire-hit NSW.

Specialist defence personnel will be sent to advise NSW fire incident controllers at each of the 14 control centres around the state, Prime Minister Scott Morrison said in a statement on Friday.

Those personnel would be able to free up ADF resources such as bulldozers, bulk water carriers and troops for NSW firefighting use.

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"We'll continue to do everything in our power to ensure our fireys have the resources and support they need," Mr Morrison said.

Mr Morrison said the ADF was already providing numerous services for firefighting authorities including helicopter search and rescue, transport, accommodation, meals and refuelling.

The addition of defence personnel at NSW fire control centres would help coordinate ADF logistical support, Defence Minister Linda Reynolds said.

Royal Australian Air Force bases were also supporting NSW's air tanker fleet.

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"This behind the scenes support from the ADF frees up more of our firefighters to perform their specialised roles fighting the fires," Ms Reynolds said.

Two firefighters were killed and as many as 100 houses destroyed when bushfires ripped through NSW on Thursday and Saturday last week.

At least 873 NSW homes have been destroyed this fire season.

The government's deployment of additional ADF personnel follows their decision to grant Commonwealth public service workers at least four weeks paid leave to fight bushfires in a plan to get more "boots on the ground".