Linda Reynolds says China's expansion has put Australia in a precarious position.

"They have not positively contributed to Australia's - or the region's - security and stability," Senator Reynolds told a defence forum on Thursday.

"Australia has watched closely as China has actively sought greater influence in the Indo-Pacific.

"Australia is far from alone in being troubled by this."

The government is spending another $270 billion on defence over the next decade to protect against China's militarisation and the fallout from coronavirus.

It has also instructed the Australian Defence Force to focus squarely on the region, rather than far-flung conflicts.

Peter Jennings from the Australian Strategic Policy Institute believes the country could be heading to a potential military crisis off the coast of China within the next year or two.

"What is new is the realisation that the risk of conflict is upon us right now, not a comfortably distant 20 years away," he said.

"The (defence strategic) update abandons a long-held strategic view that we would have 10 years of 'strategic warning time' to prepare for a large-scale conflict."

Mr Jennings has also urged the prime minister to apply his strategic lens to Australia's "thin diplomatic effort" in Southeast Asia.

"We must work with the region to show that it's possible to push back against (Chinese) domination," he said.

Senator Reynolds does not believe Australia's concerns will surprise the Chinese government.

"We have been very clear in expressing our concerns about developments that are inconsistent with international law or may undermine the sovereignty of nations," she said.

Scott Morrison repeatedly referenced the 1930s and the lead-up to World War II when he announced the extra spending and strategic shift.

The prime minister dismissed concerns Beijing might see his comments as a comparison between China and fascist Germany or imperialist Japan.

"That would be a misreading of my remarks," he told reporters.

"What I talked about was the conflation of economic uncertainty and global instability.

"There are similarities, but there are other parts of the analogy which are different, but the impact is similar."

Before her speech, Senator Reynolds said Australia's security environment was changing "very, very quickly" and the region was becoming less safe.

She said while the prospect of high-intensity conflict in the region was still unlikely, the possibility was less remote than in the past.

"We have not changed, our values have not changed, and how we engage with the region has not changed," Senator Reynolds told ABC radio.

"But the region has changed and China's behaviour has changed in the region."

Tensions between the US and China have put the Indo-Pacific on edge.

So too have border skirmishes between China and India, and Beijing's intransigence over the South China Sea.

Australia is also concerned China is exercising "soft power" by offering Pacific nations unsustainable loans, which critics describe as debt traps.

Australian Associated Press