The head of the World Health Organization urged an international expert group Monday to conduct a frank and critical review of its handling of the swine flu pandemic.

A small but vocal minority of scientists and government officials around the world have accused WHO of overplaying the danger of the virus, while others have claimed its decision to declare a pandemic was unduly influenced by commercial interests.

"We want a frank, critical, transparent, credible and independent review of our performance," WHO director general Margaret Chan told the experts assembled for a three-day meeting in Geneva.

Still, reporters were barred from parts of the proceedings and news photographers were kept outside for the duration of Monday morning's meeting.

The outcome of the review would help the global body better prepare for future disease outbreaks, Chan said.

WHO's top flu official acknowledged that close public scrutiny would likely continue into the handling of the outbreak by the UN body and governments worldwide, but insisted it was easy to criticize with hindsight.

"We have a great deal of speculation, we have a great deal of criticism," Keiji Fukuda told the meeting. "The reality is a huge amount of uncertainty."

"In many ways, it is more unforgiving out there," he said. "The expectations are higher."

Anger has been growing in many countries over the perceived waste of public funds as vast stocks of unused vaccines near their expiry date.

Fukuda said fears during the early days of the outbreak of the H1N1 pandemic virus were heightened by concerns that swine flu could be as dangerous as the H5N1 bird flu strain, which kills more than half of those infected. So far, the death rate from swine flu has been much lower, with about 17,700 deaths confirmed worldwide over the past year out of millions of infections.

Suggestions for improvement expected

The review will be conducted by 29 scientists and public health officials who Chan said were vetted for conflicts of interest. It will include Prof. John Mackenzie of Curtin University in Australia, who was also a member of the WHO emergency committee that Chan consulted before declaring the pandemic.

The review panel is chaired by Harvey Fineberg, president of the Institute of Medicine in Washington. The group's members are "authorized and indeed required to exercise independent judgment," he told The Associated Press.

Any recommendations made to WHO wouldn't be binding, he said, as member states have the final say about changes to the way the global body operates.

But he added: "I fully expect there will come suggestions for improvement."

The experts' initial findings will be presented to WHO member states in May. A final report will be published next year.