The UN health body the World Health Organization (WHO) said in a statement on Saturday that "there is no public health justification for postponing or cancelling the games" due to the Zika virus in Brazil.

WHO said that postponing or cancelling the games would not "alter the international spread of Zika virus" given that the mosquito-borne virus is already in 60 countries.

WHO's comments come a day after 150 health experts from around the world issued an open letter urging the global health body to delay or cancel the games in Brazil, where the virus has hit the hardest.

Zika has been linked to microcephaly in babies and neurological problems, although most people only experience a slight fever.

The nearly half a million people expected in Brazil for the games could become infected and act as a vector to spread the disease to "poor, as-yet unaffected places" in Africa and South Asia, the health experts wrote.

"An unnecessary risk is posed when 500,000 foreign tourists from all countries attend the Games, potentially acquire that strain, and return home to places where it can become endemic," they said.

Failing to cancel, postpone or move the games would be "irresponsible" and "unethical," the experts said.

WHO noted, however, that people continue to travel between countries with the virus. There are also those who do not travel, for a number of other reasons. WHO has already urged pregnant women not to attend the games and in February called the virus a global health concern.

The health experts questioned a possible conflict of interest because of WHO's relationship with the International Olympics Committee. They called for an unbiased, evidence-based assessment to guide the UN health body.

Moving the Olympics in such a short time period is not practical and cancelling or postponing the games would entail massive economic losses.

cw/jm (AFP, AP, dpa)