The prime minister will make a televised address at 8pm to address rises in COVID-19 case numbers.
Parliament is also set to be recalled to sit on Wednesday, Downing Street confirmed.
A No 10 spokesman said: “The spread of the new variant of COVID-19 has led to rapidly escalating case numbers across the country.
“The prime minister is clear that further steps must now be taken to arrest this rise and to protect the NHS and save lives.
“He will set those out this evening.”
The move comes after Nicola Sturgeon announced that a nationwide lockdown will be introduced in Scotland from midnight on Monday.
Sturgeon said the new curbs are being introduced to contain the new, faster-spreading strain of the virus.
She said there will be a legal requirement for people to stay at home for the rest of January.
Schools in Scotland will remain closed to pupils until the start of February at the earliest.
She told MSPs in Holyrood: “It is no exaggeration to say that I am more concerned about the situation we face now than I have been at any time since March last year.”
Johnson said earlier on Monday that tougher restrictions would be announced soon, as cases continue to surge across the country.
Speaking during a visit to Chase Farm Hospital in North London, where he met some of the first people to receive the new Oxford University/AstraZeneca COVID-19 vaccine, he said there were “tough, tough” weeks to come and acknowledged there was “no question” that further measures would be necessary.
Watch: Matt Hancock ‘very worried’ about South African variant
The latest data shows a 41% rise in the number of confirmed coronavirus patients in hospital in England between Christmas Day and January 3, a figure that has caused alarm in Whitehall and the health service.
“If you look at the numbers there’s no question we will have to take tougher measures and we will be announcing those in due course,” Johnson said.
On Monday, the UK saw its highest ever daily case toll of 58,784, with 407 more people dying from the virus.
It was the seventh day in a row that more than 50,000 new coronavirus cases were reported, as hospital admissions continue to rise.
With 78% of England’s population already under the toughest current restrictions, ministers have been examining how successful the Tier 4 measures – which came into force for the first time on December 20 – have been.
The announcement follows calls from teachers unions and ministers to close schools to stop the mutant COVID virus spreading.
Time to act: thread on why we need to close schools, borders, and ban all household mixing RIGHT AWAY.
— Jeremy Hunt (@Jeremy_Hunt) January 4, 2021
Former health secretary Jeremy Hunt called for immediate action to close schools, shut borders and ban household mixing, saying the situation was “off-the-scale worse” than previous winter crises faced by the NHS.
“In the face of exponential growth even waiting an extra day causes many avoidable deaths so these plans must now be urgently accelerated,” he said.
Senior Tory Neil O’Brien said procedures “need to toughen up at the border” in order to prevent cases being imported – a particular concern given the potential for new variants such as the one in South Africa.
On Monday, health secretary Matt Hancock refused to rule out the prospect of another national lockdown for England.
He told Sky News: “We don’t rule anything out, and we’ve shown repeatedly that we will look at the public health advice and we will take the public health advice in terms of what is needed to control the spread of the disease.
“This new variant is much easier to catch, it is much more transmissible, and we’re now seeing the effect of that in lots of different parts of the country, unfortunately.
“And it means that whereas the old Tier 3 was able to contain the old variant, that is proving increasingly difficult in all parts of the country.”
PM will be directly addressing the nation. It won’t be a press conference. Tier 4 restrictions will be imposed everywhere. Schools closed. No more team games in parks. But outdoor exercise will still be allowed. https://t.co/dhKbH2lkgC
— Robert Peston (@Peston) January 4, 2021
ITV political editor Robert Peston tweeted that schools will be closed and Tier 4 restrictions will be imposed all over the country.
He tweeted: “PM will be directly addressing the nation. It won’t be a press conference. Tier 4 restrictions will be imposed everywhere. Schools closed. No more team games in parks. But outdoor exercise will still be allowed.”
Watch: Boris Johnson to address the nation tonight to address further steps to combat variant