The New Zealand government is looking at how it can give extra support to Tonga, which has declared a zika epidemic.
Tongan authorities have confirmed two people there have contracted the mosquito-borne virus, and at least another 250 are suspected of having it.
The Australian government has pledged more than half a million dollars in extra aid to Tonga to try to stop zika spreading.
New Zealand's foreign minister Murray McCully said officials were investigating how New Zealand could best assist.
"We're considering the support we give Tonga at the moment. We have formal aid talks for the year over the next few days and I have specifically asked our negotiators to talk about what is going to be useful to assist them.
"We already fund a lot of regional projects in this space but we will look at what we can do bilaterally as well," he said.
A journalist in Tonga said the Kingdom would need a lot more support to cope with the zika virus.
News agency Matangi Tonga Online's Mary Fonau said health authorities were focusing on cases involving pregnant women.
She said authorities are testing them and not others, because of cost.
She said health workers have been around spraying schools to get rid of the mosquitos which carry the virus.
Women encouraged to delay pregnancy in the Cook Islands
The Cook Islands Ministry of Health is encouraging women to delay pregnancies as the Zika virus continues to spread across the Pacific.
The Cook Islands had a Zika outbreak in 2014 and while there have been no cases reported recently, nearby Tonga has declared an epidemic.
The Cook Islands News reports the community health services director, Doctor Neti Herman, as saying while there was no strong evidence that Zika was causing microcephaly, the ministry was suggesting women should delay getting pregnant.
She said the 2014 outbreak took three months to control.
Dr Herman said whether there were any babies born during that period with microcephaly is not yet clear.
The zika virus has been declared a global health emergency by the World Health Organisation.