New Zealand troops were forced to step in for ineffective Hungarian troops in a neighbouring Afghanistan province, a leaked diplomatic cable says.

The Wikileaks cable from US Ambassador to Afghanistan Karl Eikenberry describes escalating violence, drug problems and power struggles in the "wild, wild west" of Baghlan province.

It says the Hungarian Provincial Reconstruction Team (PRT) stationed there do little to combat trouble in the region.

When insurgents caused a "security situation", New Zealand troops from the neighbouring Bamyan province had to cross the border to deal with it, the cable says.

"The Hungarian PRT does little to address any of these problems. They are not permitted to fire their weapons except in self-defence, do little more than patrol the main roads and undertake no counter-narcotics activities. When two Hungarian de-miners were killed doing their work, Budapest stopped sending mine clearers.

"When the security situation in northeastern Bamyan Province was threatened by Baghlan-based malefactors, it was the New Zealanders who had to cross into Baghlan to address the problem."

Though direct attacks are still uncommon in Baghlan, criminals have linked with the Taleban, the cable says.

It also alleges locals are hiring themselves out to the Taleban insurgency.

Despite that, Hungarian forces are focussed on "getting home unscathed" after doing short stints of small-scale development work in the area, it says.

A Defence Force source says working in Baghlan is consistent with the "direction" of the New Zealand Provincial Reconstruction Team in Afghanistan.

New Zealand troops did not engage in combat on behalf of the Hungarian forces, he says.

"On a small number of occasions, a limited number of PRT personnel crossed into Baghlan to carry out key leader engagement and talk to the locals. This is consistent with the PRT direction, and is with the approval of the Task Force Commander and the Hungarian PRT."

The New Zealand PRT is located in the town of Bamian in the Bamyan Province.

Its most recent six month rotation arrived in October.

Government has announced defence teams will remain in Afghanistan until September 2011.