Nicola Sturgeon today insisted people should 'assume' there will be Omicron cases in Scotland as she warned more travel curbs could be needed in the coming days.
The SNP leader said there had been no infections with the 'super-mutant' identified north of the border so far.
But she stressed that was not likely to continue, and the authorities 'may need to go further on restricting travel'.
Asked on the BBC's Andrew Marr show whether she would look at closing the border with England, Ms Sturgeon said that was difficult - but pointed out that in the past the Scottish government had advised against travelling between the UK nations.
That could happen again in a 'last resort', she said.
On the possibility of more restrictions, Ms Sturgeon said: 'I think we need to be open-minded to doing anything that is needed to keep the population safe right now.'
The Health Secretary said the government was taking 'proportionate and balanced' precautions to 'buy time', confirming that masks will be compulsory again in shops and on public transport in England from Tuesday. That is already the case in Scotland.
Nicola Sturgeon today insisted people should 'assume' there will be Omicron cases in Scotland as she warned more travel curbs could be needed in the coming days
Boris Johnson announced changes to testing and isolation rules, and mandatory masks in shops and on trains in England in a bid to prevent the spread of the highly transmissible new variant
According to a message on the passenger locator form section of the Government's website, day two tests for arrivals in the UK will also need to be PCRs rather than lateral flows from 4am on Tuesday.
But Mr Javid stressed there is no certainty that the 'super-mutant' strain will be able to dodge vaccines, or to what extent that could happen.
And asked whether there could be a return of even tougher curbs such as social distancing, he said there the government is 'nowhere near' that.
Urging people to keep planning for the festive season as they have been, Mr Javid told Sky News: 'It's going to be a great Christmas.'
The Cabinet minister said he was still only aware of two Omicron cases in the UK.
Mr Javid said the government will consider updating the recognised symptoms for Covid, after being told on the BBC's Andrew Marr show that reports in southern Africa suggested people did not lose sense of smell or taste and suffered more fatigue.
'We will of course if we need to,' he said.
The reassurance effort came after Boris Johnson announced changes to testing and isolation rules, and mandatory masks in shops and on trains in a bid to prevent the spread of the highly transmissible new variant.
At a hastily-arranged Downing Street press conference last night the PM painted a grim picture of the potential threat from the new 'super-mutant' strain - admitting he cannot guarantee Christmas will go ahead as hoped.
Mr Johnson put unlocking in reverse as he extended travel bans, enforcing day-two PCR tests for arrivals in Britain, and making facemasks compulsory in shops and on trains.
All arrivals to the country must self-isolate until they get a negative result from a gold-standard test - which can identify those carrying Omicron.
All contacts of people infected with the variant must stay at home for 10 days.
Sajid Javid desperately tried to cool panic over the new variant today, insisting it is 'going to be a great Christmas ' and the UK is 'nowhere near' proper lockdown
Mr Javid said this morning he hopes extra measures will be 'temporary', adding he thinks people will 'take this more seriously'.
Speaking to Trevor Phillips On Sunday on Sky News, Sajid Javid said: 'Doing it in this proportionate way where it's for public transport, it's for retail outlets, I think is the right level of response on masks.
'It will be via Government regulation and that means, I think, that people will take it seriously.'
Pressed on whether people will following the rules on masks, Mr Javid said following the news of a new variant: 'I do think people will take this more seriously.'
Mr Javid added: 'It's important, I think, to act in a proportionate way and also in a temporary way.