The bidding process for the 2026 World Cup has been postponed amid allegations around the 2018 and 2022 tournaments.
The decision was due to be made in Kuala Lumpur in May 2017.
Swiss prosecutors are investigating alleged financial irregularities concerning the 2018 and 2022 events, in Russia and Qatar respectively.
The United States are considered favourites to stage the 2026 World Cup, but Canada, Mexico and Colombia are also thought to be interested.
Australia and China are ineligible because successive World Cups cannot be hosted by nations from the same confederation.
Both countries are members of the Asian Football Confederation – as is 2022 host Qatar.
Russia and Qatar were selected for 2018 and 2022 at a secret ballot of Fifa’s 22 executive members in December 2010.