The Australian government has assured on Friday that the announced defence spending cuts in the upcoming 2012-2013 budget will not weaken the ability of the military to safeguard the country's interest in the Asia-Pacific region.

Earlier on Thursday, Prime Minister Julia Gillard revealed that the Defence Ministry will have to postpone up to $4 billion of projected expenditures in order for the federal government to meet its goal of realising a budget surplus of about $1.5 bullion next year.

Ms Gillard, however, stressed that the budget reduction will not compromise the military's capability to react and be deployed where and when it is needed.

"The budget will protect the men and women on the front line," the prime minister assured while adding that the Australian military's present strength in numbers will not be shrunk under the new Defence Force Posture Review.

The new defence white paper, which the government said would be fully completed in the next two years, merely recalibrated the domestic and international security concerns of Australia, which now focuses on areas more proximate to the country.

According to Defence Minister Stephen Smith, the upgraded review is more geared toward the importance of international engagement, giving special significance of Australia's "engagement in the Pacific and in Asia in forthcoming years."

In conjunction with the new white paper and the government's lower spending program, Mr Smith has revealed on late Thursday that the country will have to put off planned military procurements, which will delay the delivery of 12 F-35 Joint Strike Fighter (JSF) by another two years.

Canberra was scheduled to receive the new combat planes from U.S. defence contractor Lockheed Martin by 2017 at the latest until the new defence spending recalibration.

In announcing the decision, Mr Smith said that the U.S. Defence Department has been informed in advance with assurances that the move will not in any way impact on the bilateral dealings of Canberra and Washington.

The defence minister noted too that America has readjusted its planned purchase of the JSF fighter planes, which reportedly pushed back the U.S. timetable for acquiring up to 150 units of the stealth combat aircraft.

"We are now essentially on the same timetable for the delivery of our first batch of joint strike fighters as the United States is," Mr Smith was reported by Agence France Presse (AFP) as saying on Thursday.

Yet at the same time, the defence chief downplayed suggestions by the Coalition and some analysts that the planned defence cuts would leave the country vulnerable to future threats or aggressions.

"The (Defence) White Paper 2009 makes it clear there's no foreseeable threat to Australia in terms of an attack," the Australian Associated Press (AAP) reported Mr Smith as saying on Friday.

"I don't think we've got people circling Australia thinking about an invasion by 2028," he added in deflecting the theory pushed forward by the opposition that supposedly points to a regional conflict over the next decade.

The new defence white paper, Mr Smith admitted, as well as the spending adjustments would inevitably spawn difficult periods for the Australian military in the immediate years ahead but he insisted that "it's manageable."

"We believe that we have ring-fenced the core capability that we need and the core contributions and obligations that we have at the moment so far as our field operations are concerned," the defence chief said.

Still, opposition treasury spokesman Joe Hockey warned that taking away considerable amounts from the defence department would in the long-run affect the deployment of the country's frontline troops.

"(The spending cuts) are going to impact on our frontline defence forces," Mr Hockey told ABC on Friday.

"In defence force terms, you need to have the latest equipment as fast as you possibly can," the Liberal frontbencher added.