The head of the World Health Organization(WHO) expressed concern over the speed of the omicron variant of COVID-19 spreading around the world.

WHO Director-General Tedros Adhanom Ghebreyesus said in a media briefing on Tuesday that almost 90 million cases of COVID-19 have been reported to the WHO since the omicron variant was identified ten weeks ago, which is more than the total number of cases reported in 2020.

Saying that the WHO is concerned with the narrative taking hold in some countries that prevention of transmission is no longer possible or necessary, he added that it is premature for any country to either surrender or declare victory against the virus.

The WHO chief called on countries to continue testing, surveillance, and sequencing, stressing that more transmission means more deaths, and that the dangerous virus will continue to evolve.

Tedros also shared that the WHO is currently tracking four sub-lineages of the omicron variant, including BA.2, also called the 'stealth' omicron variant.

Sunday marked two years since the WHO declared COVID-19 a public health emergency of international concern, the highest level of alarm under international law.