The two teams had been set to meet in Vannes on Monday (AEDT) in the new tournament, a coronavirus-enforced replacement for the scrapped autumn internationals brought on by the global pandemic.
However, Fiji, which on Friday (AEDT) revealed that two members of its travelling party had tested positive for COVID-19, have now reported further cases affecting close contacts with the squad.
Without any room in the schedule for the fixture to be rearranged, the result will be decided on Monday, with the likely options a 0-0 draw or a 28-0 bonus-point win for France.
Fiji's match with Italy in round two – set to take place in Ancona on 22 November (AEDT) – is also now in doubt.
"This was a difficult and disappointing decision, but it was the only possible outcome following today's test results," Ben Morel, chief executive of tournament organiser Six Nations Rugby, said in a statement.
"Whilst we've all been eagerly awaiting this match, the welfare of our players and their support teams remain our number one priority.
"In this instance, it is impossible for the Fijians to field a competitive team and we have no other option but to cancel this match. I want to thank the Fijian and French Unions for their collaboration and wish the impacted athletes a speedy recovery."