The Omicron variant has now been detected in 106 countries, according to the latest weekly epidemiological report from the World Health Organization.

U.S. President Joe Biden announced on Tuesday the opening of more federal vaccination and testing sites to tackle the surge in COVID-19 cases sparked by the Omicron variant, and said some 500 million at-home rapid tests will be made available to Americans for free starting in January.

The Indian central government on Tuesday said there were initial signs of a surge of COVID-19 cases and increased detection of the Omicron variant, and asked all states to "activate war rooms".

Another 15,363 Omicron cases have been found in Britain, the biggest daily increase since the COVID-19 variant was detected in the country, taking the total number of Omicron cases found in the country to 60,508, the UK Health Security Agency confirmed on Tuesday.