Fifa president Sepp Blatter has told an emergency meeting of football's governing body he will not quit, amid growing politicalpressure over a corruption scandal.
Seven top Fifa officials were arrested in Zurich on Wednesday, among 14 people indicted by US prosecutors.
UK PM David Cameron urged Mr Blatter to resign but Russian President Vladimir Putin has backed him for a fifth term.
Fifa's congress has opened. The vote for president will go ahead on Friday.
Michel Platini, the head of Uefa, the European football governing body, had asked Mr Blatter to resign after the crisis talks in Zurich, which involved heads of the six international confederations. The president refused.
Mr Platini later said that if Mr Blatter were re-elected, Uefa might have to discuss its relations with Fifa.
Key sponsors have expressed concern over twin corruption investigations by both the US and Swiss authorities.
Uefa threatThe emergency meeting was Mr Blatter's first appearance since the crisis began on Wednesday.
He was not among the 14 people who were charged by the US authorities on Wednesday with racketeering, fraud and money laundering.
At a Uefa news conference later, Mr Platini said he had asked Mr Blatter "as a friend" to resign, saying: "I have had enough - enough is enough, too much is too much.
"I say these things with tears in my eyes. I don't like it this way. But there are just too many scandals."
But the president told Mr Platini it was too late, as Fifa's congress was about to start. The opening ceremony has now begun in Zurich, with Mr Blatter in attendance.
Uefa agreed at its meeting on Thursday to throw its weight behind Jordan's Prince Ali bin al-Hussein, Mr Blatter's only challenger, in Friday's vote.
Mr Platini said that if Mr Blatter won, Uefa could hold an extraordinary meeting in Berlin at the time of the Champions League final.
When asked if this could include withdrawing from Fifa competitions, Mr Platini said: "We will raise all possibilities."
Pressed on the possibility of a World Cup boycott, he said: "There may be proposals. I honestly don't wish that."