The UK Department of Health and Social Care (DHSC) has announced that "an urgent meeting of G7 health ministers will be convened" later on Monday "to discuss
the developments on Omicron", a new variant of the coronavirus.
The gathering, which will be held "under the UK presidency", comes after a third Omicron case was recently confirmed in Britain, when an individual tested positive after travelling to London.
The UK Health Security Agency (UKHSA) said that a person, who had already left Britain, had links to travel in southern Africa and that targeted testing is now being conducted in places the individual visited, including the central London borough of Westminster.
She insisted that vaccination is "critical" to help UKHSA bolster its "defences against this new variant", urging people to wear face coverings in crowded places, including public transport and shops, "to ensure we all help break the chains of transmission and slow the spread" of Omicron.
The remarks came after Prime Minister Boris Johnson announced fresh measures to contain the spread of COVID-19 following the detection of two cases of the Omicron strain in the UK.
Speaking at a Downing Street briefing on Saturday, Johnson said that those arriving in Britain would now have to take a PCR test for the coronavirus on the second day and self-isolate until they have received a negative test result.
Anyone who tests positive with a suspected case of the new variant is obliged to self-isolate for ten days, regardless of their vaccination status, according to Johnson.
The prime minister also confirmed the reintroduction of face masks on public transport and shops, adding that they will not be required in hospitality venues.
He stressed that the new measures would be "temporary and precautionary", and that they would be reviewed in three weeks.
The World Health Organisation (WHO) has, meanwhile, asserted that there isn't enough data yet to state that the new Omicron coronavirus variant is more dangerous than the Delta strain.
"The number of people testing positive has risen in areas of South Africa affected by this variant, but epidemiologic studies are underway to understand if it is because of Omicron or other factors", the WHO said in a statement.
On Friday, the UN health agency identified the new strain, first detected in South Africa, as one of concern, as it is reported to be more transmissible and possibly more dangerous. The WHO dubbed it Omicron, the 15th letter of the Greek alphabet.
The new variant prodded Britain to impose a travel ban on ten African nations, among them Angola, Botswana, Eswatini, Lesotho, Mozambique, Malawi, Namibia, South Africa, Zambia, and Zimbabwe.