A "majority" of football federations support increasing the number of teams playing at the 2022 World Cup in Qatar from 32 to 48, Fifa president Gianni Infantino said in Doha on Thursday.
Speaking at a press conference after a three-day Fifa summit in the Qatari capital, Infantino said the idea had widespread backing from associations across the globe.
"We will see," he said. "So far, of course the majority is in favour because 16 more teams to participate, not only means 16 more countries with World Cup fever but also 15 or 16 more countries being able to dream.
"Is it feasible or not, that's the question?"
Fifa has said it will make its final decision in March after the completion of a feasibility study.
He said that is open to the idea of a 48-team World Cup.
Any decision to extend the tournament would be faced by logistical and political problems.
The 2022 World Cup, the first in the Middle East, will take place over 28 days not the usual 32, as in Russia earlier this year.
Infantino confirmed that changing the number of days is not a possibility in Qatar, so one option would be to host tournament games across the region.
But that is complicated by Qatar being at the centre of the worst diplomatic crisis to hit the Gulf in years.
Since June 2017, it has been politically and economically isolated by neighbouring former allies, including Saudi Arabia, United Arab Emirates and Bahrain.
They accuse Qatar of supporting terrorism and being too close to Iran.
Doha says its rivals are seeking regime change in Qatar.
Asked if he had held specific conversations with Qatari organisers or political leaders about holding some games in Saudi Arabia, Infantino said: "We discuss about everything but we didn't decide on anything concrete yet."