On Sunday, 86 cases of the new variant were recorded, bringing the UK's total to 246.
Sixty-eight of these were discovered in England, and the other 18 in Scotland, where there are now 48 confirmed cases in total, the UK Health Security Agency (UKHSA) has said.
On Saturday, a change to travel rules was announced in a bid to slow the spread of the new variant.
Nigeria was added to the travel red list, which will go into effect from 4am Monday, 6 December.
On Saturday evening, Mr Javid tweeted: “From 4am Monday, only UK and Irish citizens and residents travelling from Nigeria will be allowed entry and must isolate in a managed quarantine facility.”
From 4am Tuesday, all people travelling to the UK from the country will have to take a pre-departure test, regardless of vaccination status, he added.
Earlier this week, people were ordered to wear masks in shops and on public transport and 10-day isolation periods were reintroduced for people in contact with the new variant, regardless of their vaccination status.
However, a government scientific advisor today said it is “too late” to make a “material difference” to a potential wave of omicron cases.
He said: “If omicron is here in the UK, and it certainly is, if there’s community transmission in the UK, and it certainly looks that way, then it’s that community transmission that will drive a next wave ... but I think it’s too late to make a material difference to the course of the omicron wave if we’re going to have one.”
Dr Katherine Henderson, the president of the Royal College of Emergency Medicine, also warned that the NHS will be in a “very, very difficult position” if the Omicron variant causes a surge in hospital admissions.
She said that the situation is already “spectacularly bad” and likely to become worse
She added: “We will always still be there. We still want patients to come but we do have to help people to understand that really at the moment the service is so stretched that an extra push could be very very difficult.”
Additional reporting by PA
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