The World Health Organisation (WHO) has announced that the countries battling the Zika virus must implement new tools to prevent it from spreading.

The virus is mainly linked to severe birth defects in thousands of babies in Brazil and has dramatically increased.

The UN agency noted that the countries should work on controlling the population of mosquitoes that are responsible for carrying the virus.

WHO Vector Control Advisory Group has evaluated a genetically modified (GM) prototype mosquito that could be used to control the spread of the virus.

The advisory panel has recommended further field trials and risk assessment to evaluate the impact of the new GM mosquito on disease transmission.

WHO said in a statement: "Given the magnitude of the Zika crisis, WHO encourages affected countries and their partners to boost the use of both old and new approaches to mosquito control as the most immediate line of defence."

The agency said that male mosquitoes sterilised by low doses of radiation can be released to mate with female mosquitoes in order to control the reproduction.

When male mosquitoes carrying the naturally occurring Wolbachia bacteria mate, eggs do not hatch, the agency said.

WHO health systems and innovation assistant director-general Dr Marie-Paule Kieny said: "Laboratory-based Zika diagnostics, mostly non-commercial, are already playing an important role in helping us better understand this outbreak.

"However, new validated and broadly-available diagnostics are urgently needed to step up research, clinical management and surveillance."

Several manufacturers and research institutions either involved in the development of medical tools for Zika, or interested in embarking on such research have been identified to carry out research and development on Zika.