Natalie Barr demands answers about the threats Australia faces as Albanese government boosts defence spending by $50billion

The Albanese government has been pressed to justify a $50billion funding boost for the defence force over the next decade.

Defence Minister Richard Marles unveiled the new national defence strategy and investment program on Wednesday, which includes naval upgrades.

The spending boost will provide an additional $5.7billion over the next four years and will increase defence funding to 2.4 percent of GDP by 2033/34.

It will be the largest growth in military spending since 1949, and comes despite massive borrowing and spending which has triggered runaway inflation and consequent interest rate rises.

During an interview with Mr Marles on Sunrise, host Natalie Barr asked: 'Who else besides China are we protecting ourselves from?'

'In our region, we are witnessing the biggest conventional military buildup since the Second World War, which is China; that is an inescapable fact.'

Mr Marles said the spending was required in a region which is 'less certain' due to China claiming territories, and trade routes need to be protected due to that expansionism.

Barr said others have argued this spending should have happened earlier.

'A former top bureaucrat wrote a defence paper 15 years ago and basically it sounds like he's furious that no-one listened to him. That was in 2009,' she said.

'He said, "Both sides of politics should be judged harshly here because no one listened".

'Do you accept that? He says we're starting from scratch here?'

Mr Marles put the blame on the previous government, including the failed French submarine contract.

'There was no doubt as we came into office we were met with an enormous amount of challenges,' he said.

'The best time to act on this would have been ten years ago but the second best time to act is now, and that's what we're doing.'

China has slammed the government's plans, and urged Australia to abandon its 'Cold War mentality'.

'We hope Australia will correctly view China's development and strategic intentions, abandon the Cold War mentality, do more things to keep the region peaceful and stable, and stop buzzing about China,' China's Foreign Ministry spokesman Lin Jian said. 

The security risks in the Indo-Pacific were coming from 'major countries' outside the region, Mr Lin said.

'They have been forming exclusive groupings, stoking bloc confrontation, and in particular, muddying the waters in the South China Sea, as if the world needed any more instability. China firmly opposes it,' he said.

Defending the initiative, Mr Marles said it was 'ridiculous' to suggest Australia was trying to match the strength of China and the US in the Indo-Pacific. 

'You're talking about great powers and clearly, we're not seeking to be a peer of the United States or China. Which is why... commentators who walked down that road, frankly, lack wit,' he said.

The defence strategy includes a push to widen the recruitment eligibility to non-citizens but Mr Marles said that' would not happen overnight'.

'It's reasonable to describe that in terms of years,' he told ABC's Radio National on Thursday.

'Looking at certain classes of non-Australian citizens as potential recruits for the ADF going forward is an important step that we will need to take if we're going to meet the challenge of growing our defence force through to 2040.'

Mr Marles said the government's immediate challenge was to improve conditions for Australians currently serving or thinking about joining the ADF.

'Trying to streamline recruitment to make it a better offer for Australians is what we're doing right now and that is actually having an impact,' he said.

The defence minister said there had been a fall in the number of personnel leaving the military and recruitment numbers were starting to turn around.

Speaking at the National Press Club, Mr Marles said the hundreds of thousands of New Zealanders calling Australia home was an obvious place to start.