Blatter, holding a news conference ahead of the final weekend of the African Nations Cup, repeated the view he expressed earlier this week in Madrid when he suggested that the bidding might be changed for European candidates only, but at the moment it remained open to all the candidates.
"When FIFA opened the bidding procedure for 2018 and 2022 it was open for everybody with the exception of Africa and South America because they are organizing the 2010 and 2014 World Cups," Blatter told reporters on Friday.
"We now have the candidatures of the U.S, for 2018 and 2022, four candidatures from Europe, we have Australia and then we have the Asian ones: South Korea, Japan and Qatar, Indonesia.
"There is a movement that 2018 should go to Europe.
"I said it's a possibility only if other associations do not bid. It is not a decision for the executive committee to change that right of every association to bid for a World Cup.
"But the movement to go to Europe exists."
The decision on who will stage both the 2018 and 2022 finals will be taken by FIFA's executive committee in December.
As it stands England, Netherlands/Belgium, Russia, Spain/Portugal are the four European bids for 2018 and 2022. Indonesia, Qatar and South Korea are bidding only for 2022.
Both Japan and Australia said earlier this week they were continuing with their bids to stage the 2018 edition.
Blatter said on Monday that a deal was being discussed whereby only European nations would bid to host the 2018 World finals, revealing he had talked over the proposal with Michel Platini, president of European football's governing body UEFA.
