Alarmed by the spread of bird flu beyond East Asia, nations pledged nearly $2 billion Wednesday to fight the disease, far exceeding expectations at the fundraising conference in Beijing. The United States alone promised $334 million.

Just after the conference ended Wednesday, host China reported bird flu had killed a 35-year-old woman who had handled sick chickens. She was the country's sixth known victim.

The World Bank had appealed for at least $1.5 billion to stave off a potential bird flu pandemic. The bank has said about 45 percent of the funding would be spent in Vietnam, Cambodia, Indonesia, Thailand and Laos — countries where the deadly H5N1 strain of the virus is already endemic.

"What we've seen today is that the world really does care and wants to respond effectively to the threat of avian influenza and a possible human pandemic," said David Nabarro, the U.N. coordinator on avian and human influenza. He described the response as "quite extraordinary."

Although primarily a disease affecting poultry, the virus has killed at least 77 people in East Asia since 2003, according to the World Health Organization. With a mortality rate of over 50 percent, experts are worried that the virus could mutate into a form that spreads easily from person to person. So far, most human cases have been traced to contact with infected birds.

The Beijing meeting took on a new sense of urgency after Turkey reported four deaths from the virus this month, the first outside East Asia.

The spread of the virus from Asia to Turkey spurred European countries to raise initial commitments. The EU on Tuesday increased its commitment to $121 million, about $20 million more than it announced last week. The 25 member states were also expected to pledge about $120 million in total.

"There's no time to waste," U.N. Secretary-General Kofi Annan said in a taped address to the conference. "Let's ensure that we are ready."

The United States would take a leadership role in helping to manage the funds and ensure that they are channeled to where they can be of most use, said the U.S. coordinator for health, science and the environment, Nancy Powell.

The United States pledged the largest amount from a single country, $334 million, mostly in grants and technical assistance, while the World Bank made $500 million available in loans. The United States also said it will invest billions of dollars in the next three years to develop a human vaccine.

Japan donated $159 million, while China said it would donate $10 million.

Chinese Premier Wen Jiabao promised the communist government would be transparent and forthcoming with information about outbreaks in addition to sharing information about virus strains with the international community.

"China is ready to fully use the existing cooperation mechanisms to give countries and international organizations concerned, timely and accurate updates on the latest developments of the avian influenza epidemics," he told donors.

China was criticized for its sluggish response to severe acute respiratory syndrome, or SARS, in 2003.

Jim Adams, head of the World Bank's bird flu task force, said the $2 billion in pledges followed a demanding year for donors. Hurricane Katrina and the earthquake in Pakistan struck just months after Asia's tsunami, increasing the competition for funds.

He said the $2 billion in pledges reflected international concerns about bird flu, adding that nations needed to focus on using the money effectively.

The WHO said Swiss drug maker Roche Holding AG has agreed to donate another 2 million courses of the antiviral drug Tamiflu to help poor countries battling the disease. Tamiflu is believed to be most effective in treating bird flu in humans.

Roche last year donated 3 million courses of the drug to WHO for a global stockpile that would be distributed wherever a pandemic flu strain emerged, she said.

Company officials have said about 150 million treatments are expected to be produced this year.

The funding conference, co-sponsored by the World Bank, European Commission and the Chinese government, follows a global bird flu coordination meeting held two months ago in Geneva, which brought together participants from 100 countries.