In a draft speech to be delivered at crisis talks here, Thaksin said it was vital that the outbreak which has now spread to poultry in 10 Asian countries including China did not spiral out of control in the human population.

He encouraged nations faced with the deadly bird flu threat to take lessons from the battle plan drawn up here last April against the Severe Acute Respiratory Syndrome (Sars) epidemic that claimed nearly 800 lives.

"The enemy we face is no less deadly than Sars," Thaksin said, according to the draft.

"The lessons of Sars must not be forgotten. To contain a fast-spreading virus, countries need to respond promptly, act with transparency, obtain reliable scientific data, and share information and experiences with one another."

With his and other governments battling allegations that they covered up the outbreaks in a bid to protect their economies, he said it was vital to restore confidence in the region.

"We know from our experience with Sars that no amount of cheerleading will restore public confidence unless we can come up with concrete action, credible information and verifiable scientific evidence," he said.

Ministers and officials from the affected nations of Cambodia, China, Indonesia, Japan, Laos, South Korea, Thailand and Vietnam will take part in the discussions to begin later Wednesday.

Taiwan and Pakistan have also been hit by weaker strains of the disease -- which has claimed at least 10 lives and led to the culling or death of more than 20 million chickens -- but are not sending officials.

Representatives of the European Union and the United States, as well as Malaysia and Singapore, which have so far escaped infection, are in attendance along with the World Health Organisation (WHO), the Food and Agriculture Organisation (FAO) and the World Organisation for Animal Health (OIE).

Meanwhile, Vietnam said Wednesday that two sisters who died last week from severe respiratory illnesses had tested positive for bird flu, taking the country's death toll from the disease to eight.

Hoang Thuy Long, director of the National Institute of Hygiene and Epidemology (NIHE), said the pair, aged 23 and 30, died last Thursday from the virulent H5N1 strain of the virus.

Thaksin said the rapid spread of bird flu represented the "dark side of globalisation" and posed a grave threat to the economy as well as to public health.