Prime Minister John Key said the forces may be replaced by non-combat troops.
New Zealand is the latest partner in the Afghanistan military coalition to announced an accelerated troop withdrawal, The New York Times reported.
France announced in January it also would pull its troops earlier than had been planned.
Five New Zealand soldiers were killed in the past month along with many other coalition troops.
While New Zealand was planning an earlier-than-expected Afghanistan withdrawal, Gen. Martin E. Dempsey, chairman of the U.S. Joint Chiefs of Staff, arrived in Kabul to discuss the war.
The visit by Dempsey was characterized by NATO as one of his regular trips to Kabul. But it comes after a two week stretch in which 10 American service members have been killed by Afghan security forces in so-called green-on-blue or "insider" attacks.
Three New Zealand soldiers were killed Sunday.
Lance Cpl. Jacinda Baker, 26, Pvt. Richard Harris, 21, and Cpl. Luke Tamatea, 31, were killed when an improvised explosive device struck their Humvee on the road to Do Abe in the northeast of Bamyan Province, the New Zealand Herald reported.
The deaths came two weeks after Lance Cpl. Rory Malone and Lance Cpl. Pralli Durrer were killed in a gunfight in Afghanistan.
Key said the 145 New Zealand troops in Afghanistan would return home as early as April of 2013. New Zealand had planned to withdraw troops in October of that year.
The decision to leave earlier was apparently made before the five recent deaths, an unnamed official told The New York Times.
"While decisions still have to be finalized, it's likely it will take place in the earlier part of 2013 rather than the later," Key said.