The Rugby World Cup could be expanded to include 24 teams from the current 20 by the 2023 tournament in France, World Rugby CEO Brett Gosper says.
The sport's global showpiece has featured 20 teams since the 1999 tournament in Wales and the same number will compete next year in Japan.
"We're always looking from an expansive point of view rather than reducing, so it's just a question of when rather than if," Gosper told British media.
"We want to make sure the teams are competitive enough to move to a 24-team tournament. We have assumed 20 for 2023 but we could change that between now and 2023.
"The tendency for us is to try and look to expand. It's about growing the global game -- getting interest from fans and commercial interest in new markets.
"But you've got to make sure you've got the teams. We're definitely in an expansive mindset, is how I'd put it."
Even with 20 teams the tournament has regularly faced criticism for serving up too many routs of smaller rugby countries that qualified through regional playoffs.
At the 2015 World Cup, Pool A whipping boys Uruguay were thrashed 54-9 by Wales, 65-3 by Australia, 47-15 by Fiji and lost 60-3 to hosts England.
For next year's tournament in Japan, 19 teams have booked their places with the 20th to be decided at a repechage tournament in Marseille in November.
Gosper said how the lower-tier nations like Georgia and Namibia perform in Japan could prove to be a factor in expansion plans.
"If those teams have a good tournament it would give courage and impetus to change," he added.