Zurich - FIFA president Gianni Infantino all but wrote off the chances of an expanded 48-team competition at the 2022 World Cup in Qatar on Wednesday.
Last month Infantino told the Asian Football Confederation's annual congress in Kuala Lumpur that increasing the number of teams from the 32 that made up the tournament in Russia this year was "feasible".
However he appeared to backtrack on that during an interview with AFP and other media in Zurich.
"I haven't changed my mind," said Infantino.
"I was positive about it from the beginning because I think if we can increase the number of teams it is good for football. That is why we are going to do it for the 2026 World Cup.
"Can we do it for 2022? It is a difficult challenge."
Accommodating another 16 teams would vastly complicate Qatar's task in preparing for the World Cup, which was awarded to the tiny desert state in 2010.
"We are in discussion with Qatar," said Infantino, who said the tournament would need to spread to neighbouring countries.
"It will be a very, very difficult challenge to do it only in Qatar.
"So personally, as president of FIFA, I would be very happy if some matches could be shared with some countries in the region."
The question of regional cooperation has been complicated by Qatar's stand-off with neighbours Saudi Arabia, Bahrain and the United Arab Emirates, who have cut off diplomatic relations and imposed a blockade on the resource-rich country, accusing it of endorsing terror activities.
"In the light of current circumstances in the region I would be even happier if it could happen," he said.
"Football unites, builds bridges, that could be a concrete result.
"What are the chances? Certainly small but what is wrong in discussing it?" said Infantino.
A final decision will be made in March at the next FIFA Council in Miami before the draws for qualifying are made.