New Zealand will screen any children and their families from Nauru according to UN guidelines before accepting them under the refugee quota, Prime Minister Jacinda Ardern says.

Ardern made the comments today after Australia's Home Affairs Minister Peter Dutton warned that 13 children detained on the island had family members who failed security screening by United States authorities.

"We do apply a screening process. UNHCR [the United Nations' refugee agency] is involved to ensure that individuals are bona fide refugees and then we apply our own screening process," Ardern told reporters today.

Australian Prime Minister Scott Morrison has said this week he might be open to accepting New Zealand's long-standing offer to take up to 150 people detained on Nauru but has rejected any horse-trading with the opposition Labor Party in Canberra over it.


Dutton told Parliament yesterday there were now only 52 children on Nauru.

"We want to get it to zero, but we have to be sensible about the way that we do it."

Labor had written to the Federal Government asking it to consider amendments to legislation that would pave the way for Australia to take up New Zealand's offer, he said, including guaranteed acceptance of the offer and the removal of all children and their families from Nauru to New Zealand.

"Let me say this, there are 13 children on Nauru at the moment who are involved in family groups - they are adults, mostly males within that family unit - that are the subject of adverse security assessments from the United States.

"The first question is, is New Zealand going to take those people when the United States has advised that that person, that individual in the family unit, is a risk to national security," Dutton said.

Labor wants a proposed lifetime ban on re-entering Australia to apply only to those refugees on Nauru resettled in New Zealand, not other countries.