The best way to combat a major outbreak of bird flu in humans will be discussed by experts in London.
The virus has not been contained in Asia
The World Health Organization says a pandemic of bird flu is inevitable and could cause 50,000 deaths in the UK.
It has warned that efforts to contain the spread of the current strain of the virus circulating in Asia have not been successful.
Indonesian authorities confirmed the first three human fatalities from the disease in the country on Wednesday.
Dr Dick Thompson, a WHO expert on bird flu, said the H5N1 variant of the virus currently circulating in Asia had the potential to become a more deadly form.
"It jumps from animals to humans occasionally and when it does it causes severe disease.
"If it acquires the ability to move easily from person to person it could ignite a pandemic.
"It hasn't been contained, it seems to be spreading more widely. Recently we had reports of the virus turning up in migratory birds in western China."
Dr Thompson said the bird flu virus was very unstable, and its genes were always changing - that alone might be enough to trigger the creation of a more deadly form.
Alternatively, if the virus infected an animal or human also carrying a standard form of flu the two viruses could swap genes in a process called reassortment.
If this happens the consequences could be dramatic.
"It would cause a lot of people to become very sick, very suddenly and it has the potential to overwhelm healthcare systems, and cause a lot of social disruption."
Dr Thompson said there was no way to stop a pandemic - if H5N1 did not mutate into a more deadly form, then it was only a matter of time before another variant did.
Dr Sandra Bell, director of homeland security for the Royal United Services Institute for Defence and Security Studies, said the UK was closely monitoring the situation, working on diagnostic techniques and putting in place contingency plans to ensure vital services would be maintained.
"We don't know when it is going to come, or what it is going to be like, but we have put a lot of planning and preparation in place so that we can move very, very quickly in order to minimise the impact."
Dr Bell said an effective vaccine could only be produced once the exact nature of the mutated virus became apparent.
"You cannot have a vaccine unless you have identified the strain, so you have got to wait until it has started, which is where you rely on your surveillance and quick diagnosis techniques to identify the strain very rapidly, and quickly produce a vaccine."