The bid from the United States, Mexico and Canada remains the only proposal so far to host the 2026 event, but FIFA's ruling council on Tuesday opted to give other possible bidders a further three months.
While no rival bid has so far emerged, there have been media reports that Morocco could join the race.
The three North American federations had asked for "in principle" backing for their bid and an exclusive "window" to put together the details of their plan before final ratification in 2018.
A source with knowledge of the meeting said that plan had met with resistance with some FIFA Council members arguing that more time was needed to allow for any eventual alternative.
FIFA's current rotation policy states that the continental confederation which held either of the previous two events cannot bid, ruling Europe and Asia out of the initial 2026 running.
Potential bidders have until August 11 to submit their bids with a vote scheduled for the 2018 FIFA congress in Moscow.
The FIFA statement said that should that congress not select any of the candidates then federations from Asia and Europe would then be invited to bid.
It would, however, be a major surprise if a potentially money-spinning North American bid were to be rejected.
FIFA have also voted to expand the World Cup to 48 teams for the 2026 edition, requiring more facilities to handle the increase to 80 games while also opening the door to joint bids.
The North American proposal is for 60 games in the U.S. with Mexico and Canada each getting 10 early-stage matches.
(Reporting by Simon Evans; Editing by Toby Davis)
