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

The World Bank had appealed for at least $1.5 billion to stave off a potential bird flu pandemic that could kill millions worldwide.

David Nabarro, the U.N. coordinator on avian and human influenza, described the $1.9 billion in pledges as “quite extraordinary.”

“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,” he told reporters.

The World Bank has said about 45 percent of the funding would be spent in Vietnam, Cambodia, Indonesia, Thailand and Laos - countries where the H5N1 virus already is endemic.

Although primarily a disease affecting poultry, the virus has jumped to humans, killing 77 people in East Asia since 2003. 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.

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

“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.