Credit agencies Standard & Poor's and Moody's said Australia's AAA rating with a stable outlook was not in danger after the government unveiled its budget, with deficits seen as moderate and declining. 

Australia is one of only a handful of nations to hold the top rating and S&P said its stance was not changed by a deficit expected to come in at $35.1 billion, or 2.1% of GDP, in 2015-16. 

This was below analysts' expectations of more than $40 billion with the conservative government continuing to forecast a return to surplus by 2019-20. 

S&P noted that sharp falls in Australia's key export commodity prices were hurting revenues but said that "nonetheless, Australia's budget performance over the next few years appears likely to improve, underpinned by spending restraint".

"While weaker, these revised budget forecasts remain broadly consistent with our base-case assumptions that deficits will be moderate and declining," it added. 

"We continue to anticipate that net general government debt will remain low relative to GDP," the agency said. 

Moody's said the measures and forecasts announced were in line with its expectations, "which underpin our stable outlook on Australia's AAA rating". 

"In Moody's view, Australia's sovereign credit profile continues to benefit from economic and fiscal buffers built up over two decades of robust growth, which cushion the impact that the current, more challenging environment has on its sovereign credit metrics," it said.

Australia was the only advanced nation to dodge recession during the global downturn but is currently in the midst of a major transformation as a Chinese-driven mining investment boom winds down. 

The budget forecast the economy would remain below-trend at 2.75% in the coming financial year before lifting to around trend growth of 3.25% in 2016-17.