NZ may send more troops to Afghanistan

New Zealand could send more troops to Afghanistan but would do so only as part of an overall exit-strategy, Prime Minister John Key said.

He said the United States had a global "shopping list" to institute a "surge-type plan, on the basis that they had in Iraq, to try and get on top of the situation and then ultimately to exit out".

"We could do it. Why would we do it? Well I guess the argument would be if it was part of an exit strategy - I don't want to stay in Afghanistan forever," Mr Key told the TV One channel on Monday morning.

New Zealand already has a large contingent in Afghanistan and would need more details of the US plan before making a further commitment, he said.

He rejected claims the government would supply the extra troops to keep the US happy.

"We have 140 people there; we can't leave them there in isolation... The challenge is how do we get out of Afghanistan."

Foreign Minister Murray McCully confirmed on Sunday the US had asked New Zealand for additional help in Afghanistan, particularly from the SAS and civilians.

New Zealand's elite SAS troops have had three previous missions to Afghanistan, the last being in 2006.

Mr McCully said the government was going to consider its resources, and take into account the rollover of the provincial reconstruction team of about 140 Defence Force personnel that was already operating in Afghanistan and would be there until at least September next year.

"Remember Afghanistan is not our biggest deployment; Timor-Leste is. We've got significant numbers of people in the Solomons, we've seen trouble in Tonga, we've seen trouble in other places."

Mr McCully said he was not including Fiji in that scenario.