British nationals travelling to the UK from high-risk countries will have to quarantine in a hotel, under plans to be discussed by ministers.
The BBC understands the proposals, expected to be discussed on Tuesday, could see people bussed to hotels on arrival.
Boris Johnson said ministers were "actively working on" the idea, amid concern over new coronavirus variants.
Most foreign nationals from high-risk countries already face UK travel bans.
These include South Africa and Brazil, where new variants of the virus were recently discovered, as well as a number of countries near them.
Whitehall sources said those quarantining in hotels would have to pay for the costs of their own accommodation.
Hotel quarantine is already in place in countries including New Zealand and Australia.
Under current travel curbs, almost all people must test negative for Covid-19 up to 72 hours before travelling to be allowed into the UK.
Even after this negative test, arrivals still have to quarantine for up to 10 days, although this can be done at home.
In England, this self-isolation period can be cut short with a second negative test after five days.
Have you stayed in a quarantine hotel? Share your experiences.
On Monday, Scotland's First Minister Nicola Sturgeon confirmed officials around the UK had discussed a "four nations" approach to the issue.
She added that hotel quarantine was "under active consideration" by Scottish ministers, and would be discussed at a cabinet meeting on Tuesday.
The Northern Ireland Executive is also expected to discuss travel rules when it meets on Tuesday.
Speaking on Monday, Mr Johnson said the UK already had "one of the tightest regimes in the world" but the government wanted to "protect this country from reinfection from abroad" during the rollout of the vaccines.
Asked who exactly would be required to self-isolate in hotels, he said: "We need a solution that gives us the maximum possible protection against reinfection".
"We have to realise there is at least the theoretical risk of a new variant that is a vaccine-busting variant coming in," he told reporters.
"We've got to be able to keep that under control".
The policy is among the measures credited with limiting cases of coronavirus in Australia - whose population is around 25 million - to just 28,777 positive cases during the entire pandemic.
This is a smaller number of new cases than are currently recorded in the UK every day - with a daily average of over 33,000 in the past seven days.
How might the system work?
In Australia, travellers are allocated a hotel room on arrival and taken there by bus. Often, entire flights are accommodated in the same hotel.
The New South Wales government pledges to make "every attempt" to find suitable accommodation for travellers and families. But availability of rooms means there are severe limits on the number of people who can arrive into the country on any given day.
The hotel quarantine lasts a minimum of 14 days up to 24 days, providing a person tests negative twice.
The cost of the quarantine is borne by the passenger - at around £1,700 per adult and £2,800 for a family of two adults and two children - and billed after the quarantine in completed.
Fees are waived for those who can prove they are unable to pay, and there are certain exemptions.
But not following the rules is a criminal offence, and in New South Wales carries fines of around £6,000 for individuals, six months in prison, or both with an additional £3,100 fine for each day the offence continues.
Ministers have been facing pressure to toughen up the UK's borders in recent weeks, with Labour accusing ministers of "dragging their feet on setting vital protections". On Monday the party's shadow home secretary Nick Thomas-Symonds backed the idea of using hotels to help "prevent the importation of further strains of the virus".
Accusing ministers of a "lack of strategy," he said the UK "continually acts too slowly and without proper planning in place."
"This continued failure is leaving the door open to new strains of Covid-19, putting people at risk and undermining the sacrifices everyone is making to address this virus."