Washington, Jan 07 (Agencies): US Defence Secretary Robert Gates on Thursday announced $78 billion in cuts to military programmes over the next five years, intended to curb the Government's ballooning budget deficit. The move is key part of its "reform agenda".

"We must come to realise that not every defence programme is necessary, not every defence dollar is sacred and well-spent, and that more of nearly everything is simply not sustainable," Gates said.

Overall, the Army, Air Force, Navy and Marine Corps have identified a combined $100 billion in savings over the next five years that can be spent on more pressing needs.

Over the same period, $78 billion will be slashed outright from the defence budget, which is expected to flatten out, after being adjusted for inflation.

Gates said the measures will meet the White House goal of limiting the defence budget in 2012 to $554 billion. Those figures do not include the cost of military operations in Iraq and Afghanistan.

The cuts will include reducing the size of the Army by about 40,000 soldiers and the Marines by 15,000 to 20,000, Gates said.

The biggest weapons system to get the axe was the Marine Corps' amphibious assault vehicle, which has already cost about $3 billion and been beset by technical problems and production delays.

Elimination of the programme will save another $11.5 billion estimated for military contractor General Dynamics to develop and deliver the so-called Expeditionary Fighting Vehicles.

The Marine craft was designed to carry up to 17 troops across a body of water, landing on shore and driving inland, well beyond enemy beach defences.

In initial estimates of $9 billion for 1,000 of the vehicles, but cost overuns had pushed the estimate to $14.5 billion to deliver only 574 vehicles.

Also coming under scrutiny is the Marine Corps version of the F-35 fighter. The Marine F-35 is meant to take off and land almost vertically, unlike the versions being employed by the Navy and Air Force.

The Marine F-35 has been experiencing technical problems and development delays. Gates said he was putting the programme on a two-year probation, recommending that it be eliminated if the problems cannot be overcome in that time.