Prime Minister Scott Morrison said work was under way on a further support package for flood victims, on top of previous financial assistance

In the past week more than 163,000 claims have been made to the government, with more than $193.5 million spent in disaster recovery payments.

Mr Morrison said as many as 2000 ADF personnel had been deployed to flood-affected areas, and that will increase to 5000 in coming days.

"ADF assistance includes airdrops of food and supplies into isolated communities, and helping clear roads to restore essential services like power and internet," Mr Morrison said on Monday.

"We know more support will be required, especially in Lismore and surrounding districts, where flood levels are reported to have peaked above all known records. In Lismore, it is not just a flood event, it is a catastrophic event."

However, some locals in affected communities have said their experience was different and they had not witnessed ADF support.

Operation Flood Assist commander, Major General David Thomae, said 637 personnel from the ADF were on the ground in NSW, while 1458 were in Queensland.

A further 656 defence personnel will arrive in northern NSW areas within the next 24 hours.

Defence forces have carried out 113 flood rescues and 79 helicopter missions.

Major General Thomae said the ADF's actions had saved lives.

"We have done all we can with the conditions we have been faced with," he told reporters in Sydney.

"I'm very sorry for all of those people who have felt they haven't been supported. I empathise completely with their plight, the scale of devastation has been extraordinary.

"We have been pushing into (inaccessible communities) as much as we can since the start of the flood event and we continue to do so."

The government has also been criticised for not spending money from its $4.8 billion emergency response fund on flood mitigation measures in the wake of the disaster.

NSW Premier Dominic Perrottet said he would welcome any additional funding for flood-affected areas, should the federal government decide to use money from it.

"If you're going to use that fund for a disaster, you're not going to get a bigger disaster than this one," he said.

"What has occurred up here is an unprecedented catastrophe."

Opposition Leader Anthony Albanese also attacked the government for not allocating funds to help deal with floods in areas such as Lismore.

"The government has completely failed to act in advance, even though the warnings were there, just like they have failed to act on disaster recovery," he told reporters in Adelaide.

"Lismore has been flood affected many times. There's a reason why much of the housing in Lismore is elevated."

Further rain is expected along the NSW coast, hampering recovery efforts.

The federal government has already supplied a $558.5 million support package to parts of Queensland to help recover from the floods, while a similar package delivered more than $434 million to NSW.

Of the disaster recovery payment claims that have been made, 89,000 have been granted in Queensland, while NSW had 74,000 claims granted.

Government Services Minister Linda Reynolds the significant number of claims made in recent days reflected the scale of the disaster.

"The Morrison government has acted swiftly," she said.

Deputy Prime Minister Barnaby Joyce described the flooding in northern NSW as extraordinary.

"Now that the water is going down and people are asking how they can get their lives back together ... that is where we are really going to kick in and take information and work out how we do it," he said.

Australian Associated Press