Prime Minister John Key has confirmed that the Government intends bringing New Zealand troops back from Afghanistan in April 2013 before work begins on the rebuilding of Bamyan airport.
Japan is set to start the work in May and New Zealand troops would not be able to leave by air after this time.
Moving the 145 personnel by road is unsafe, particularly as they would most likely be travelling in unprotected vehicles.
Mr Key says the Cabinet will decide the exact date of withdrawal in the next few weeks.
Labour Party leader David Shearer supports the plan to bring the troops home earlier than September.