The three soldiers killed instantly by a road bomb on Sunday were riding in a Humvee borrowed from the United States, which no longer uses the vehicles in combat.
However Chief of Defence Force Lieutenant General Rhys Jones says that no one would have survived the blast in an MRAP.
The bodies of the three dead soldiers, Corporal Luke Tamatea, Lance Corporal Jacinda Baker and Private Richard Harris, are due to arrive in Christchurch this afternoon on an RNZAF C-130 Hercules.
A service for them is expected to be held at Burnham on Saturday.
They were carried from Bagram Air Base in Afghanistan by an Australian Defence Force A-340 after a ramp ceremony attended by the Commander of the International Security Assistance Force (ISAF), General John R. Allen, and the visiting US chairman of the Joint Chiefs of Staff, General Martin E. Dempsey, several hours after the base had been attacked by insurgents' missiles.
Mr Key refused to be drawn on another statement by the Hungary Ministry of Defence which has issued a second statement to again deny claims its provincial reconstruction team isn't pulling its weight.
The statement also expresses condolences over the deaths of New Zealanders in Afghanistan on Sunday.
But it has again denied claims that it does not patrol at night in Baghlan province or in areas near the border of Bamiyan where New Zealand is based and where insurgents are thought to be increasing. After the deaths of two New Zealand soldiers earlier this month, Prime Minister John Key suggested that insurgent problems were growing in the border between the provinces because the Hungarians refused to patrol at night.