Scotland’s First Minister spoke at a briefing on the variant after the Scottish Government announced four cases are in Lanarkshire and two in the Greater Glasgow and Clyde area.
She said some of the cases identified have no travel history, which suggests there is a degree of community transmission, but there is currently no suggestion this is either sustained or widespread.
Ms Sturgeon and her Welsh counterpart, Mark Drakeford have jointly written to the Prime Minister proposing stricter travel restrictions to help combat the spread of the new variant.
We are clear that a four nations approach to issues such as border restrictions is the most effective approach
Nicola Sturgeon and Mark Drakeford
They propose arrivals to the UK have to self-isolate for eight days, with tests on day two and day eight.
Currently, passengers arriving in the UK from 4am on Tuesday will be required to take a PCR test by the end of their second day from entry and isolate until they receive a negative test, while 10 southern African nations have been added to the red travel list.
The First Minister also said she and Mr Drakeford had asked Boris Johnson to hold an urgent Cobra meeting with representatives from the four UK nations and to guarantee the Treasury will fully fund any business support required.
The letter states: “The emergence of Omicron poses a potential threat to the UK.
“It is clear that the strain is already here and that it appears highly transmissible.
— Scottish Government (@scotgov) November 29, 2021
“We need to work collectively – and effectively – as four nations to take all reasonable steps to control the ingress of the virus to the country and then to limit its spread.
“We are clear that a four nations approach to issues such as border restrictions is the most effective approach. This requires that a meeting of the Cobra committee be held as soon as possible.”
Addressing the situation in Scotland, Ms Sturgeon urged people to “prepare for the worst” but said she was hoping for the best.
She said Public Health Scotland and local health protection teams are working together and “enhanced” contact tracing is being undertaken to establish the origin of the virus and any individuals the people have come into contact with in recent weeks.
All close contacts of suspected Omicron cases will be advised to self-isolate for 10 days, regardless of their vaccination status, and enhanced testing will take place in areas where cases have been confirmed.
Ms Sturgeon said much is still to be learned about the new variant, adding: “What we do know at this stage confirms in my view that we should treat it seriously and that we should continue to act on a precautionary basis at this stage.
“While we all hope that the emerging understanding of it will reduce rather than increase our level of concern, there is no doubt that this presents potentially the most challenging development in the course of the pandemic for quite some time.
“It’s important to prepare for the worst. That does not mean that we are not hoping for something considerably short of the worst. We are still hoping for the best.”
Ms Sturgeon said compliance with restrictions is “vital”, and urged people to get fully vaccinated, take regular lateral flow (LFD) tests and adhere to the rules around mask wearing, ventilation and hygiene as well as working from home if possible.
Questioned on the possible impact on Christmas gatherings, she is not asking people to put plans on hold at the moment, but added: “On any occasion that you are intending to socialise or mix with people from other households… please do use an LFD test.”
Earlier, Scotland’s Health Secretary, Humza Yousaf, said: “There is still much to learn about the Omicron variant. Questions remain about its severity, transmissibility and response to treatments or vaccines and scientists are working at pace to provide additional information.”
The first two cases in the UK – in Nottingham and Essex – were announced on Saturday, while a third Omicron case was detected in the UK on Sunday in a person with travel links to southern Africa.
Britain will convene an urgent meeting of G7 health ministers on Monday to discuss the variant first detected in South Africa amid concerns it could spread rapidly and partially evade existing jabs.