There are currently five New Zealand fire fighters in the field, with a sixth travelling to help battle the fires currently ravaging Australia's eastern states.

"These people are specialists helping in air attack and heavy machinery supervision, safety, and managing interstate deployments," Fire and Emergency NZ manager Paul Turner said.

Ardern said Australia would receive more support from its trans-Tasman neighbours if they needed it.

"Our thoughts are with Australia right now, these are devastating fires," she said on Monday afternoon.

"I contacted Prime Minister Morrison this morning just to touch base and offer New Zealand's full support.

"He acknowledged that on one of his visits he had actually spoken to one of the New Zealanders already over there

"I've made the offer, to definitely let us know if further support is required. We're working through an additional request ... for additional fire fighters."

Australian Associated Press