Treasurer Jim Chalmers has vowed to make the federal budget more sustainable during the parliamentary term, flagging a fresh look for the country's finances.
After handing down his first budget on Tuesday, Dr Chalmers warned difficult decisions lay ahead in order to reduce deficit and secure funding for key services like Medicare and the NDIS.
He said there were many structural issues that still needed to be addressed.
"We need a fresh look at the budget in its entirety," he told the ABC's Insiders program on Sunday.
"We've shown that you can move sensibly on all fronts, restraint, trimming spending, sensible tax reform, you can make the budget more sustainable and that will be the task of the two or three budgets remaining in this parliamentary term."
The treasurer said $22 billion in savings had already been found since the government came to office in May.
Dr Chalmers said Treasury had begun work on reviewing the petroleum resources rent tax.
While intake from the tax is set to be up by $200 million this financial year, revenue is set to fall off.
"We do want to make sure that Australians get a good return for their resources," he said.
"We need to balance that against the investment that's been made into the sector. When I get that advice from Treasury. I'll engage with it in a meaningful way."
The treasurer also said Australia's finances needed to be improved in order to make services like the NDIS more sustainable going forward.
It's forecast the NDIS is set to cost more than $100 billion a year in coming years, but Dr Chalmers said it was still value for money.
"First and foremost we want to provide the service to Australians with a disability and their families, it's crucial that we do that," he said.
"Part of ensuring that is to make sure that the scheme is sustainable and that's why the work that (NDIS Minister Bill Shorten) is doing is so important."
