Prime Minister Julia Gillard vowed on Thursday to beef up Australia's defence capabilities amidst pressures to reduce government spending in the May 8 budget presentation.

"The Government is committed to delivering one of the most capable defence forces in our region with the people and equipment we need to do the job, including the joint strike fighters, the new amphibious ships, the new submarines and our air warfare destroyers," Ms Gillard was reported by the Australian Associated Press (AAP) as saying in presenting the Labor government's new defence white paper.

The new defence plan, Ms Gillard said, effectively replaces the white paper previously issued in 2009 but keeps at the same time the 'core concerns' that would boost Australia's military might, as presented in the first paper.

The full version of the new defence white paper will be out by mid-2013, Ms Gillard assured, and should include the bolstering of the country's maritime capabilities.

As recommended in the 2009 paper, the Defence Ministry would best serve the interests of the country if it would be able to acquire 12 new advance submarines, which will increase the country's ability to safeguard it presence in the Asia-Pacific region.

"In our strategic environment we need strong maritime capabilities and that's why we need a potent submarine force," Ms Gillard.

Along that line, the Prime Minister revealed the allocation of $214 million that will finance the engineering phase of the new submarines, which federal authorities said would most likely be constructed in South Australia.

It will be a long undertaking for the defence department, Ms Gillard admitted, adding that "decisions on design questions are the most critical."

The actual submarine acquisition, Ms Gillard added, will take decades to be realised and the initial design funding "will go to essential studies which will inform the government's final decision on submarine design and workforce requirements."

Hopefully, the defence project would take on a much solid ground before Australia's existing fleet of six Collins class submarines were decommissioned on 2025.

The submarine acquisition, according to Defence Minister Stephen Smith, will be governed by "absolutely methodical and exhaustive," procedures en route to the vessels' actual assembly in South Australia.

"All of our experience is that 80 per cent of the problems in capability are caused in the first 20 per cent of the life of the project," Mr Smith told AAP.

He added that three reputable contractors from Europe have been invited to tender their proposals for the submarine designs, which could adapt existing submarine standards, derive from the Collins features and functions or adopt altogether a new submarine blueprint that would fit with Australia's requirements.

Not only that the planned acquisition will boost the country's regional defence power, Ms Gillard noted, but it would also fire up South Australia's local economy during the course of the submarines' construction.

"This will be a big injection into manufacturing and the development of our skills base," the Prime Minister pointed out.