The United Nations' top health official says the worldwide spread of swine flu is now unstoppable.
World Health Organisaton head Margaret Chan was speaking at a global forum in Mexico, where the virus first took hold.
Leaders and experts from 50 countries are in Cancun for the two-day meeting to discuss strategies for combating the virus. It has been more than two months since the initial alert over swine flu.
Since then, the H1N1 virus has entered more than 100 countries, infected more than 70,000 people and killed more than 300 worldwide.
The WHO says most H1N1 cases are mild, with many people recovering unaided.
"As we see today, with well over 100 countries reporting cases, once a fully fit pandemic virus emerges, its further international spread is unstoppable," Dr Chan said in her opening remarks.
She stressed that the overwhelming majority of patients experienced mild symptoms and made a full recovery within a week, often in the absence of any form of medical treatment.
The exceptions, she said, were pregnant women and people with underlying health problems, who were at higher risk from complications from the virus and should be monitored if they fell ill.
NZ confirmed cases
The number of confirmed swine flu cases in New Zealand stands at 912, up 87 since Thursday.
However, the Ministry of Health says the true number is certain to be higher, as tests are not being taken from every person suspected of having swine flu.
The ministry says the number of people going to the doctor over flu generally is still rising. It says the consultation rate is considerably higher than peak rates in the past two years.
Wellington, Canterbury and Auckland have most cases of swine flu.
Health authorities in Otago and Southland say it has now been detected throughout that region also.