Messi said Brazil, Germany, France, England and Spain are always labelled favourites to win but the forward feels France and Brazil are the best two teams going into the November 20th-December 18th tournament.
"We always say the same great teams ... but, if I have to choose, Brazil and France are the two great candidates to win the World Cup," Messi told DIRECTV Sports.
"They've had the same group (of players) for a long time, working well. France, aside from the last Euros when they were eliminated (in the last 16) and did badly, they have some impressive players.
"They have a clear idea and the same coach (Didier Deschamps). Brazil is a bit the same (under Tite)."
Messi did not mention Argentina, who are unbeaten in 35 matches, among the favourites even though Lionel Scaloni's side won the Copa America last year by beating Brazil in the final.
But Argentina have been recently hampered by injuries to key players Paulo Dybala (28) and Angel Di Maria (34).
Scaloni described club football's fixture congestion in October as "terrible" but urged his players not to hold back to avoid the risk of injury ahead of the World Cup.
"We are in quite a difficult stage. The players are playing a lot of games," Scaloni told AFAestudio. "There can be problems as there are injuries (and) suspensions. It's part of being an elite player and a national team player.
"I worry, but there is little you can do. I believe that the player has to go out on the pitch to play and not think about what's coming - it can be detrimental. Let them play naturally."
Argentina face the United Arab Emirates in November in their final warm-up match before heading to the World Cup where they play their opening Group C game against Saudi Arabia on November 22nd. Mexico and Poland are the other teams in the group.
