It comes amid growing speculation France could be the next major holiday destination to have its quarantine-free travel corridor revoked owing to a spike in Covid cases.
Speaking during a visit to Northern Ireland on Thursday (13 August), the prime minister said health officials were reviewing the latest infection data from France.
He also insisted any more, while painful, would be essential to preventing cases of Covid-19 being reimported into the UK.
"We have to be absolutely ruthless about this, even with our closest and dearest friends and partners – I think everybody understands that," said Johnson.
"We will be looking at the data a bit later on this afternoon [Thursday], looking exactly where France and other countries are getting to. We can’t be remotely complacent about our own situation."
Johnson continued: "Everybody understands that in a pandemic, you don’t allow our population to be reinfected, or the disease to come back in.
"That’s why the quarantine measures are very important, and we have to apply them in a very strict way."
Hundreds of thousands of British holidaymakers escape to France every summer, and any change in France’s quarantine status would come at what would traditionally be peak summer travel season.
Last month, Spain’s quarantine-free travel corridor was revoked with just six hours notice, causing widespread disruption and dismay for the travel sector, and sending consumer confidence plummeting.
The Bahamas, Belgium and Andorra have all since been removed from the UK’s safe travel list. The Foreign Office is also advising against all but essential travel to all four countries.
