New Zealand is considering increasing aid to Tonga to help contain the spread of the Zika virus.

Australia has pledged $500,000 to help Tonga stop the spread of the virus. Tonga last week declared an outbreak, after five cases were confirmed and 259 suspected.

US President Obama will ask Congress for US$1.8 billion ($2.72 billion) to combat the Zika virus through mosquito control programmes, vaccine research and education.

Prime Minister John Key said this morning Ministry of Foreign Affairs and Trade (Mfat) officials were looking at what help New Zealand might give.


"I know Australia has put in additional funding, obviously we are concerned about what we see, and it's not outside the realms of possibility that we would do that," Mr Key said.

Australia's Minister for the Pacific, Steven Ciobo, said stopping the spread of the virus in the Pacific was essential to protect Australia.

Zika was declared an international health emergency last week, with the WHO citing a "strongly suspected" relationship between the virus in pregnancy and microcephaly, a condition in which infants are born with abnormally small heads.

Foreign Minister Murray McCully said scheduled aid talks for the coming year would be held this week.

"I have specifically asked our negotiators to talk about what is going to be useful to assist them."

Mr McCully said he did not have information on what the options for increased support could be.

Zika, identified more than 50 years ago, has alarmed public health officials in recent months as it is potentially linked to thousands of cases of brain defects in newborns.

Estimates are the virus will infect up to four million people in the coming year.

In New Zealand, there have been 10 Zika cases -- eight confirmed -- this year, affecting travellers arriving from Tonga, Samoa, and American Samoa.

Health authorities have stressed that the threat in New Zealand is virtually non-existent because of the lack of the mosquito species, Aedes aegypti, which is spreading the disease.

Air New Zealand has joined a growing number of airlines offering fare flexibility to pregnant travellers worried about travelling to Zika virus-affected areas.

The airline said customers who were pregnant, and their travelling companions, could change their tickets if they met certain criteria.

If ticketed before January 22, passengers can change the date of travel without penalty or change their travel to another of the airline's destinations without penalty, although any difference in fares would apply.

? Anyone wanting more information can call Healthline 0800 611 116 or visit the Safe Travel website, and the Ministry of Health website,