The French government has demanded to see England and Ireland's virus containment plans before it allows France to travel for Six Nations games.
"We absolutely need the necessary guarantees from these countries," said sports minister Roxana Maracineanu.
"Other nations' virus framework must respect the same requirements."
The French government has given the go-ahead to France's opening fixture against Italy in Rome on 6 February.
However, it is concerned about the new, more easily spread variant of the virus that was first identified in the UK.
France are due to play Ireland in Dublin on 14 February before their final away match of the tournament against England on 13 March.
Six Nations organisers are holding talks with French officials in Paris, outlining the measures they plan to keep teams safe.
Various contingency plans have been reported in recent weeks including hosting the whole tournament in one country to limit cross-border travel and moving the Six Nations to the summer should the planned British and Irish Lions tour of South Africa be postponed or cancelled.
The Womens' Six Nations, which usually runs across the same weekends as the men's, is set to be moved back to April.