A top FIFA official has admitted Brazil might not be ‘totally ready’ for the start of the World Cup in 70 days.
But secretary general Jerome Valcke has stressed that fixtures will not be cancelled.
Issues surround stadiums in Porto Alegre and Sao Paulo – which is set to host the opening game between Brazil and Croatia on June 12. Neither venues are finished.
Preparations for the World Cup have been beset by problems with a construction worker falling to his death last week at Sao Paulo's Arena Corinthians, which is due to host the opening match between Brazil and Croatia.
That took the number of fatalities at the site to three after two died in November following a partial collapse of the stadium. A total of eight men have already died working on World Cup stadiums.
Elsewhere, Porto Alegre's local mayor had previously said the city may drop out if additional funding was not found to build facilities for media, sponsors and fans. The city's Beira Rio stadium is due to host five matches during the tournament.
But Valcke said: "For Porto Alegre, an agreement was made between the different parties in the city to make sure the temporary facilities would be financed, so it is now more the implementation of these decisions.
"In Sao Paulo, it's sad because a worker died a few days ago and the result is that the work has been stopped inside a stadium where there are a number of things to do."
Valcke, who visited Brazil last week, added: "There is no way we can postpone the opening game. We have a match schedule and it will go until 13 July so there cannot be any delay.
"Maybe there will be things which will not be totally ready at the beginning of the World Cup but the most important thing for the 32 teams is the training camp and fields, all of this will be there to ensure you have football.
"Then we have to make sure television can get the international feed [of games] and we have to have all the telecommunication systems in place for the media, all the structures you need when you move from a normal stadium to a World Cup stadium.
"You have no choice, you have to make sure that if you are not getting 100% you have 99.99% and that's what we are working on."