John Key says NZ will take 150 refugees from Australia if required

New Zealand could be used as a resettlement option for refugees now on Nauru (pictured) and Manus Island in Papua New Guinea. Photo/ Supplied

New Zealand would take 150 refugees each year from Australian detention centres each year if asked to, Prime Minister John Key says.

Ahead of the Australian election on Saturday, Labor leader Bill Shorten said New Zealand could be used as a resettlement option for refugees now on Nauru and Manus Island in Papua New Guinea.

Mr Shorten told ABC-TV that discussions should be first held with the UN High Commissioner for Refugees, but New Zealand was "a resettlement nation".

Opposition Labor Party leader Bill Shorten on the campaign trail. Photo / AP

The 150 quota was agreed between Mr Key and former Australian Labor Prime Minister Julia Gillard in 2013 but has never been used.

"In the instance that Australia decided to invoke that provision we would allow that to happen," Mr Key said today when asked about Mr Shorten's comments.

"But at this stage that hasn't been something that Australian governments have wanted to take up."

In January, 28 refugees on Nauru wrote to Mr Key, asking to be resettled in that country under the Australia-New Zealand agreement.

In response, Immigration Minister Michael Woodhouse said it was up to Australia to decide how to resettle people from its offshore detention camps.

Australian Prime Minister Malcolm Turnbull has said resettlement in New Zealand could be an incentive for asylum seekers to board boats.