Former Labour leader Phil Goff knows what it's like to bury a loved one killed in action in Afghanistan.

The Labour MP has called for troops to come home within months, after Cabinet approved New Zealand's Bamiyan-based Defence Force staff extending operations into the hostile Baghlan province.

Baghlan was the base of the insurgents who killed Lance Corporals Rory Malone and Pralli Durrer, and injured six other Kiwi soldiers in a firefight this month.

Goff - whose nephew Matt Ferrara became the first New Zealand citizen killed in Afghanistan when he died in an ambush in 2007 while serving in the US Army - attended Malone and Durrer's funerals, and says further combat deaths are futile.

"Sometimes you do things that involve sacrifice, but the sacrifice has to be worthwhile," Goff said.

"To me, further sacrifices aren't going to bring better outcomes for Afghanistan. I've been to every funeral for those killed in action and they are terribly sad and your heart goes out to the families. But can I look them in the eye and say your son died because it was critical for us to be in Afghanistan? I don't believe I can."

Seven New Zealand soldiers have died on active service in Afghanistan, a deployment that over the past five years has cost $185 million, with $32m budgeted this year.

Goff said our exit should be done over months, to help Bamiyan locals during the transition process. While he admired those who had done a "good job in trying conditions" in the Provincial Reconstruction Team, Afghanistan was slipping towards civil war, so the time was right to prepare to pull out.

As Opposition leader before the 2011 election, Goff pledged Labour would pull out. "We didn't get elected, but we are saying it is time to go ahead of an orderly transition, and that should be months, not longer."

For most of the Defence Force's stay in Afghanistan, Bamiyan has been considered one of the safest regions, but tensions have risen as the Taleban continues to increase its presence. Coalition troops have also been attacked by members of the Afghan National Police and Afghan National Army - the men they are there to train.

"It is symbolic of the whole problem," Goff said. "It is a huge concern when the people you are working alongside obviously have Taliban infiltrators within them."

He said success in Afghanistan relied on a local administration that could capture the "hearts and minds" of its people. The Karzai administration had failed on that front, and Goff said it was "deeply corrupt".

"It is involved in drug trafficking, supports war lords, and hasn't got the support of the people. Why are our guys dying to defend an administration of that nature?"

Prime Minister John Key has said the latest deaths will not change plans to withdraw next year. The Government announced in May the reconstruction team would leave late next year, a year earlier than originally planned. "I don't think the terrible loss we've suffered means we should leave earlier. We should continue on track," Key said.

- © Fairfax NZ News