Defence Minister Jonathan Coleman has just left Afghanistan following a secret visit to New Zealand troops in the Bamiyan province.

The minister is now in Dubai on his way home but his three-day trip was kept under wraps because of safety concerns.

Violence by insurgents in the province has escalated recently and led to the deaths of five Kiwi soldiers last month.

Lance-Corporals Rory Malone and Pralli Durrer were killed in a firefight near the northern Do Abe township and Lance Corporal Jacinda Baker, Corporal Luke Tamatea and Private Richard Harris were killed when their humvee hit a roadside bomb a fortnight later in the same area.

Coleman spent two nights at the main Kiwi Base near the Bamiyan township and one night in the capital Kabul where he held talks with International Security and Assistance Force commanders and met with Afghanistan's newly appointed defence minister.

The 140-troop Provincial Reconstruction Team are due to come home by April next year after the Government brought the date forward from 2014 in line with other nations.

Coleman said the visit was a chance for him to offer his support to the troops for the important work they were doing providing security in the province.

"It was fitting to personally express the Government's condolences for the tragic loss of five soldiers that the departing rotation Crib 20 suffered and to thank the group for the on-going professionalism it continued to display."

The minister said he also discussed New Zealand's departure from Bamiyan with the local governor and security chiefs and assessed the work that was needed before April to ensure that the gains of the past decade were sustained in the long term.

"New Zealand's decade in Bamiyan will have made a massive difference in quality of life to the people there."

Coleman also visited New Zealand's development projects in Bamiyan in the solar energy, agriculture, education and health areas.

It was his second visit to Afghanistan following a trip earlier this year.

- © Fairfax NZ News