President Barack Obama has urged FIFA to operate with integrity following Sepp Blatter's resignation and allegations of corruption.

Speaking about the FIFA crisis for the first time, Obama refused to talk about the ongoing US Justice Department investigation.

"I will say that in conversations I've had here, in Europe, people think it is very important for FIFA to be able to operate with integrity and transparency and accountability," Obama told reporters.

"And so, as the investigation and charges proceed, I think we have to keep in mind that although football - or soccer, depending on which side of the Atlantic you live on - is a game, it's also a massive business, it's a source of incredible national pride, and people want to make sure that it operates with integrity."

Blatter resigned as FIFA president following the allegations, and another election will be held later this year.