The large fire started after a live firing exercise on remote Defence Force land northeast of Waiouru in the central North Island has been put out.
Acting head of the army Brigadier Peter Kelly told Radio Live that rain overnight helped control the blaze, which started on Tuesday.
Today would be spent checking hotspots in the area.
Five commercial helicopters with monsoon buckets were used to control the fire in the rugged Three Kings area east of the Desert Road, while a New Zealand Defence Force chopper was used to move troops around.
Brigadier Kelly said the cost would be "co-shared" between the New Zealand Defence Force and the Singaporean army.
The fire started during a live firing exercise by the Singaporeans.
- © Fairfax NZ News