The head of the World Health Organization has died after undergoing emergency surgery for a blood clot in his brain.
Officials say Doctor Lee Jong-wook was 61.
Spain's health minister describes Lee as an "exceptional person" and an "exceptional director general."
The comment came at today's opening of the WHO's annual meeting of its 192 members.
Lee led the UN health agency's fight against the spread of bird flu, preparing the WHO for a potential human influenza pandemic.
Lee became ill Saturday afternoon while attending an official function in Geneva.
The WHO had said Lee would be hospitalized for "some time" and would not be able to attend the annual meeting.
Lee became director-general of the WHO in 2003.
He worked for the agency for 23 years.