World Health Organisation (WHO) chief Margaret Chan said on Thursday the world is inching closer to a full A(H1N1) or swine flu pandemic.
"Now we are not in phase six yet, but we are closer to phase six today (Thursday) than we were last week," WHO Director-General Chan said referring to the highest level of pandemic alert.
She said the global health organisation is following very closely the development of the A(H1N1) influenza situation in Europe, Asia and South America.
"We need to look at whether or not the criteria for phase six is met," she said.
According to the WHO's current pandemic alert system, phase six will mean the H1N1 flu causes sustained and community-level human-to-human transmission of the virus. So far, North America is the only region where community-level outbreak has occurred.
But a number of countries have suggested that the WHO should consider not only the geographic spread of the disease but also its severity before declaring a full pandemic.
Chan said the WHO "is receptive" to countries' concerns, but it needs to consult with experts to see how the criteria for declaring a pandemic might be adjusted.
"We need to consult with experts and see in what way we can indicate the nature and the severity of the illness without compromising, without forgetting the importance of geographical spread," she added.