The board of the World Bank endorsed $500 million in aid to help countries deal with H5N1 avian influenza, while US health officials dispersed $100 million for state and local preparedness.
The virus, while it is spreading and changing, still poses no immediate threat of a pandemic, experts stress it could do so at any time. They say it is vital to prepare emergency response teams, stockpile drugs and build up surveillance networks to detect new outbreaks.
The H5N1 virus has been found in wild birds and poultry across large parts of Turkey, particularly in poor villages stretching from Istanbul, on the borders of Europe, to Van near the Iranian and Iraqi borders.
It has killed three children in Turkey and the World Health Organisation says a total of 18 people have been infected. All had close contact with sick chickens.
Globally H5N1 has infected 147 people and killed 78 of them, according to the latest official WHO tally, which includes only four of the Turkish cases.
Thousands of birds have been
killed so far in Turkey
"As the new cases of human infection with the H5N1 virus in Turkey show, the situation is worsening with each passing month and the threat of an influenza pandemic is continuing to grow every day," Shigeru Omi, the WHO's regional director for the Western Pacific, told a meeting of Asian countries and international organisations on bird flu in Tokyo.
Indonesia reported the death of a 29-year-old woman who had tested positive for bird flu, which would bring its total to 12 deaths.
The two latest confirmed Turkish patients were a one-year-old girl and a boy aged four. Both were from southeastern Turkey and reported to be in a stable condition.
Turkey's Health Ministry said tests confirmed a third Turkish child who died last week, the sister of two teenagers killed by the virus, also had an H5N1 infection.
And one of the two boys in Ankara hospital who mysteriously tested positive for H5N1 without having any signs of illness had begun showing symptoms, said Dr Guenael Rodier, head of the WHO mission to Turkey.
"As the new cases of human infection with the H5N1 virus in Turkey show, the situation is worsening with each passing month and the threat of an influenza pandemic is continuing to grow every day"
WHO's regional director for the Western Pacific
A WHO lab in Britain ran genetic tests on samples of the virus taken from two of the first Turkish victims and found a mutation that could, in theory, help make the virus more transmissible from birds to people.
Scientists stressed they have no evidence the virus is any more dangerous yet, and said the same mutation has been seen before without causing a big outbreak. But it shows the need for careful watching and testing, they said.
The Turkish authorities have killed more than 350,000 birds in the past two weeks. A three kilometre quarantine zone has been set up around infected areas, and information broadcast via television commercials and vans fitted with loudspeakers.
The World Bank was pressing for funding to help the worst-affected countries cope, and endorsed spending $500 million, ahead of a meeting of donors next week in Beijing.
World Bank Vice President Jim Adams told Reuters that Kyrgyzstan would be the first beneficiary and would get $5 million to prepare for bird flu.
Adams was "cautiously optimistic" that donor countries will add another $1 billion at the Beijing meeting.