The World Health Organization(WHO) has voiced concern that the delta variant of COVID-19 first identified in India is becoming the dominant strain worldwide.

The WHO’s chief scientist Soumya Swaminathan said in a news conference held in Geneva on Friday that this is because of the variant's significantly increased transmissibility.

Studies suggest that the delta variant is around 60 percent more transmissible than alpha, the variant first identified in the U.K., which was found to be more contagious than the original strain that emerged in late 2019.

The WHO said the delta variant has spread to more than 80 countries and it continues to mutate as it spreads across the globe.

In the UK, delta has overtaken the alpha variant to become the dominant strain accounting for more than 60 percent of new cases, while there are concerns that delta will soon become dominant in the U.S. as well, currently making up ten percent of all new cases.

The WHO and the CDC have both designated the delta variant a 'variant of concern.'