Bird flu appears to be spreading west across Russia, but New Zealand authorities say the risk of migratory birds bringing the virus here is low, and it is more likely an infected person will introduce it.
The virus has now infected birds in Siberia, Mongolia and Kazakhstan and resulted in mass cullings.
On Monday a Russian newspaper reported that a journalist who travelled to the affected region was being tested for the virus after being admitted to hospital with a high temperature and headaches.
New Zealand virus expert Dr Lance Jennings said as long as avian flu existed there was a risk of it adapting to infect humans "more efficiently", and eventually of human-to-human transmission.
"I think we are dealing with a virus that is very promiscuous and continually changing," he said.
"It's an insidious movement globally and it's a real risk to New Zealand."
Dr Jennings said it was previously thought migratory birds were "dead-end hosts" - picking up the infection but not passing it on. Now it appeared they were capable of carrying the virus, with outbreaks of bird flu among geese in Soviet states bordering China.
Ministry of Agriculture and Forestry spokesman Dr Ron Thornton said the flu had been found in ducks and geese but they did not migrate to New Zealand. Wading birds from Alaska and Siberia did migrate here, but had not been implicated.
Dr Thornton said international experts, migration studies and MAF surveys pointed to a "low risk but we can't say anything is zero risk". It was more likely an infected person would bring it here.
World Health Organisation figures show bird flu has infected 112 humans, causing 57 deaths.
The Ministry of Health says it is working to ensure it is as prepared as possible for a pandemic, including the development of the National Centre of Biosecurity and Infectious Disease launched by Biosecurity Minister Jim Sutton this week.
The centre, near Wellington, would investigate and respond to existing, new and emerging animal diseases and those that transferred from animals to humans.
The Director of Public Health, Dr Mark Jacobs, said the ministry was getting advice from an expert advisory group on who would receive Tamiflu treatment courses in the event of a pandemic.
* The Government has committed $26 million to buying 835,000 Tamiflu treatment courses (tablets taken over a number of days).
* At present there are 470,000 treatment courses in New Zealand.
* The Ministry of Health says that by the end of the year there will be enough anti-virals to treat 21 per cent of the population.