France said on Tuesday it could tighten border controls to protect against the Omicron Covid variant, which is infecting a huge number of people in Britain.
France currently requires a negative Covid test result less than 48 hours old for arrivals from outside the European Union even if they are vaccinated.
But government spokesman Gabriel Attal said officials were "always looking at how we can strengthen our rules at the border".
A decision on stricter rules is likely in the next few days, he said.
Britain is being swept by a wave of Omicron infections that the government is trying to stem with a push for vaccine booster shots.
At least one person has died in Britain after contracting the virus mutation and UK health officials say the variant is causing around 200,000 infections each day.
Prime Minister Boris Johnson faces a rebellion by his own MPs on Tuesday as parliament votes on new coronavirus restrictions to combat the spread of Omicron.
Johnson says tougher measures are urgently needed to prevent a "tidal wave" of infections overwhelming hospitals.
