The Army's top soldier has defended the number of new light armoured vehicles (LAVs) the service has bought, saying it could not properly do its job with fewer than 105.

The Army came under fire this month for having so many LAVIIIs and for not having enough trained crews, after an audit report said it could not say how many such vehicles the Army needed because no quantity justification had been provided.

But the Chief of Army, Major-General Jerry Mateparae, said the Army needed all 105 LAVIIIs.

"Any less and we will compromise our ability to deliver and sustain a motorised light infantry battalion group," he said in the Army newspaper, Army News.

He said 57 were needed to deploy a battalion, its supporting arms and a repair and recovery group.

A minimum of 36 were needed to collectively train a second battalion group and even with that number, innovative training would be needed.

The remaining 12 were the minimum needed for individual training and to provide a repair and maintenance schedule.