China will close its borders if it finds a single case of human-to-human transmission of bird flu there, a Hong Kong newspaper reported on Saturday, while a defiant Taiwan said it would copy a patented antiviral drug.
Saving lives would be Beijing's top priority in efforts to contain a possible outbreak of bird flu, even if it meant slowing the economy, Huang Jiefu, a vice-minister of health, was quoted as saying by the South China Morning Post.
The World Bank said while prevention measures would cost a lot, the economic damage from a pandemic would be far worse.
Huang told health officials from China, Hong Kong and Macau on Friday that any suspected human case would be quarantined.
The World Health Organisation (WHO) has said the deadly H5N1 strain is endemic in poultry in China and across much of Asia, and it may only be a matter of time before it develops the ability to pass easily from human to human.
China's sheer size and its attempts to conceal the Sars epidemic in 2003 have prompted fears among some experts that it has had more bird flu cases than officially recorded.
Since breaking out in late 2003 in South Korea, the deadly H5N1 strain of influenza has killed more than 60 people in four Asian countries and reached as far west as European Russia, Turkey and Romania, tracking the paths of migratory birds.
On Friday, new cases were reported in Britain, Romania and Croatia, but there was no immediate indication it was H5N1.
In Britain, the Agriculture Ministry said a parrot that died in quarantine had contracted bird flu. The parrot had been imported from Surinam and held with other birds from Taiwan.
In Croatia, authorities prepared to cull all poultry and wild birds around a pond where the country's first bird flu case - the H5 virus in wild swans found dead - was confirmed.
Samples were sent to Britain to determine if it was H5N1, which has been found in Romania, which shares the Danube waterway with Croatia, and in Turkey.
Bosnia banned the import of poultry from neighbouring Croatia and also forbade the transport of wild fowl and poultry and the slaughter and sale of poultry in outdoor markets
The World Health Organisation's director of epidemic and pandemic alert, Mike Ryan, told the Financial Times on Saturday it would cost billions of dollars to prepare the world fully for a potential pandemic with large-scale production of vaccines and other measures.
World Bank president Paul Wolfowitz told world parliamentarians in Finland that prevention would still be far cheaper than cure.
He said Sars, despite being contained relatively early, had cost east Asian countries two or three percent of their gross domestic product for a quarter.
"Stop and think what a larger epidemic that spreads death and disease around the world would do in damage to commerce and the international economy," he said.
"The cost of prevention, while it may be expensive, would be much cheaper than the cost of dealing with an outbreak."
The Asian Development Bank said it hoped to provide $58 million to help fight the spread of bird flu - half of it to combat the virus in Cambodia, Laos and Vietnam and the rest to help international technical agencies.
India said it had started testing migratory birds for avian flu in the east. No cases have yet surfaced in the country.