It will take at least 56 million dollars until June to fight the Zika outbreak and deal with the interlinked series of infant malformations in the Americas, the World Health Organization (WHO) said in a first budget estimate.
The UN health body said the money was needed to implement its response plan for the outbreak, which includes both tracking Zika and birth defects in affected countries, as well as fighting mosquitoes that transmit the virus.
The budget and plan "will be reviewed and updated as the response evolves," WHO said.
The largest share of the money would be used for informing communities about risks and about preventing mosquito bites, which are the main mode of transmission.
The action plan also has a strong focus on boosting health care for pregnant women and to help parents of babies born with abnormally small heads and brains, also known as microcephaly.
In addition to this congenital problem, there has been a rise in cases of Guillain-Barre Syndrome, a neurological condition that involves paralysis.
The money would be shared between UN agencies, non-governmental organizations and laboratories.
WHO's Strategic Response Framework also includes funding of research into the unknown link between the usually harmless Zika fever and rising numbers of microcephaly cases.
Research and development of diagnostic tools, of a vaccine and of medicines against Zika is to be funded as well.
Zika has appeared in about 40 countries, mainly in Latin American and Pacific island countries.
It has been accompanied by a rise in reported microcephaly cases in Brazil and French Polynesia, but not in other countries where Zika has spread.
The Zika virus has been detected in babies with malformed heads, as well as in the placenta of one woman whose child had microcephaly.
However, the exact link between the virus and the congenital disorder has yet to be established, and WHO said in its action plan that there may be other, unexamined factors contributing to the connection.
In Brazil, the news portal Globo reported the country's first possible case of a foetus who died in the womb of a Zika-infected mother in Rio de Janeiro.
The respected Fiocruz medical institute would investigate the cause of death, the report said.
Brazilian authorities estimate that there are up to 1.5 million Zika cases, by far the highest national figure in the Americas.