The worst corruption crisis in football history stems from the governing body’s decision to award Russia and Qatar the next two World Cup tournaments, FIFA president Sepp Blatter has said.
Mr Blatter spoke at the Fifa congress hours before the presidential election in which he is a seeking a fifth term despite widespread condemnation of his continued leadership.
He has refused calls to resign after FIFA was targeted by US and Swiss authorities in separate corruption investigations.
In 2010, Russia was chosen to host the 2018 World Cup and Qatar was awarded the 2022 tournament amid widespread allegations of wrongdoing.
“If two other countries had emerged from the envelope, I think we would not have these problems today,” Mr Blatter said. “But we can’t go back in time. We are not prophets. We can’t say what would have happened.”
The United States was one of the losing bidders for the 2022 World Cup. On Wednesday, US authorities indicted 14 people on bribery, racketeering, fraud and money-laundering charges going back to the 1990s.
The congress was disrupted by a pro-Palestinian activist, who held up a red card and shouted “Red card to racism”.
Seven of the officials, including two serving FIFA vice presidents, were arrested in Zurich on Wednesday ahead of the congress.
The two criminal investigations have cast a new shadow on Mr Blatter’s 17-year reign as president of FIFA.
The 209 FIFA member nations will decide later today whether to stick with the 79-year-old Mr Blatter or vote for Prince Ali bin al-Hussein of Jordan.
Amid the dramatic build up to the election, Uefa president Michel Platini appealed to Mr Blatter to immediately step down – calls the president has rejected.
“I am willing to accept the president of FIFA is responsible for everything but I would at least like to share that responsibility with everyone,” Mr Blatter said in a presidential address this morning. “We cannot constantly supervise everyone in football... you cannot ask everyone to behave ethically.”
Mr Blatter also cautioned that “it will take some time” to rebuild Fifa’s reputation.
“The events of Wednesday have unleashed a storm and there was even questioned whether this congress would be organised or change the agenda,” Mr Blatter said.
“Today I am appealing to unity and team spirit so we can move forward together. That may not always be easy but it is for this reason that we are here together today.”
A two-thirds majority would be enough for Mr Blatter or Prince Ali to win the secret presidential vote, or a simple majority in a second round of voting.
Just forcing the ballot to a second round could represent a victory of sorts for Mr Blatter’s critics, denying the incumbent president an emphatic mandate in his next term.
Mr Blatter’s opening address to the congress was briefly disrupted by a pro-Palestinian activist, who held up a red card and shouted “Red card to racism”.
The protest was to draw attention to a campaign that aims to stop Palestinian players from being detained by Israeli security forces.
After calling for security, Mr Blatter announced: “I would ask you to please check the access points of this room.”
The head of FIFA's financial oversight panel has challenged world football officials to change the culture of the scandal-hit sport.
Swiss industrialist Domenico Scala told FIFA members at their meeting in Zurich that cleaning up their culture must become “part of a new DNA” for the organisation.
Mr Scala said delegates should ask themselves if they “would be comfortable if my conduct appeared in the media?”
As chairman of Fifa’s audit and compliance committee since 2012, Mr Scala has monitored all FIFA’s spending and commercial contracts.
Meanwhile, Britain's Serious Fraud Office says it is assessing "material in its possession'' relating to allegations of Fifa corruption.
It said it stands ready to “assist ongoing international criminal investigations” related to FIFA corruption.
The Serious Fraud Office would not comment on the material it is holding. Several British-based international banks, however, are mentioned in the US indictment of Fifa officials.
The fraud office is responsible for handling complex, major investigations into financial wrongdoing.
The announcement stops short of announcing that proof of criminal activity has been found.
— B/R Football (@brfootball) May 29, 2015
Swiss police said a bomb threat has been made against the venue where the FIFA congress is being held.
Zurich city police spokesman Peter Sahli says a police operation is ongoing but declined to provide further details.
An AP reporter at the scene says the Hallenstadion’s concert hall auditorium was cleared but the building itself was not evacuated.
Fifa secretary-general Jerome Valcke said “an anonymous threat against the FIFA congress was received”.
The meeting then resumed after lunch.