Australia will expand its active defense personnel by around 30% by 2040, Prime Minister Scott Morrison said on Thursday, calling it the country's largest peacetime military buildup.

The expansion will cost about AU$38 billion ($28 billion, €25 billion), the prime minister said during a visit to an army barracks in Brisbane.

"This is a significant investment in our future force," Morrison said.

"Our world is becoming increasingly uncertain, so it's important we take steps now to protect our people and our national interest over the coming decades," he said.

Over the 18-year period, the size of the Australian Defence Force will grow to 80,000 — a level not seen since the Vietnam war.

Threat from China in Indo-Pacific

Morrison said the buildup was in response to the "threats and the environment that we face as a country, as a liberal democracy in the Indo-Pacific."

Australia has been boosting its defense spending in recent years amid growing Chinese influence in the Indo-Pacific region.

Last year, the country entered a deal to buy nuclear-powered submarines from the United States and Britain under a new defense alliance, AUKUS.

The prime minister's conservative coalition government has been brandishing its defense credentials in an election year.

Opinion polls show him behind the opposition Labor party, which he has attacked as being "soft" on China.

Making Australia a 'credible partner'

Defense Minister Peter Dutton said supplementing Australia's defense capabilities was critical to make it "a credible partner" with the US, Britain, and NATO.

"If we are to rely on them, they need to rely on us," Dutton said.

Without naming any country, he reiterated warnings about the strategic threat to Australia, mainly from China.

"If people think that the ambitions within the Indo-Pacific are restricted just to Taiwan and that there won't be knock-on impacts if we don't provide a deterrent effect and work closely with our colleagues and with our allies, then they don't understand the lessons of history," Dutton said.

adi/sms (AFP, dpa, Reuters)