Gianni Infantino has indicated Donald Trump's controversial travel ban could prevent the United States from hosting the World Cup.
The United States have long been considered the favorites to win the 2026 World Cup, either on their own or to jointly host it with Canada and Mexico.
President Trump on Monday signed a new executive order banning immigration from six Muslim-majority countries, which could have implications for the nation's ability to host football's biggest tournament.
Infantino said in London on Thursday: "When it comes to FIFA competitions, any team, including the supporters and officials of that team, who qualify for a World Cup need to have access to the country, otherwise there is no World Cup. That is obvious."
Iran is the highest-ranked team in the FIFA rankings of the six affected by the executive order.
Infantino added: "Mr. Trump is the president of the United States of America and as such of course [I have] huge respect for what he does.
"He's in charge, together with his government, to take decisions that are best for his country. That's why he has been elected.
"In the world there are many countries who have bans, travel bans, visa requirements and so on and so forth.
"We are now in the process of defining the bid requirements.
"The requirements will be clear. And then each country can make up their decision, whether they want to bid or not based on the requirements.
"It's general sporting criteria."