World football's governing body FIFA says it is concerned by temporary facilities to be used during this year's World Cup in Brazil.

Temporary seats are being installed at Sao Paulo's Itaquerao stadium while a solution is being sought to cover an unpaved area of 140,000 square meters around Porto Alegre's Beira-Rio stadium.

"The biggest challenge is to have all these temporary facilities, which are subject to a lot of discussion in Brazil, in place," Valcke said in a video statement.

"Outside the stadium of Porto Alegre there is no pavement and we cannot put in place the television compound and all the different zones without any pavement.

"We are not talking about just the pavement you walk on. We are talking about 140,000 square metres and that takes at least two to three months and we are only three months away from the opening of the World Cup."

Preparations for the June 12-July 13 tournament have been beset by stadium construction delays. Three host venues - in Sao Paulo, Cuiaba and Curitiba - are yet to be ready despite an original December 2013 deadline.

"It's not only FIFA that is in a race," Valcke said. "It's the local organizing committee, the government and the cities who have to have the stadiums, their facilities and the infrastructure in the cities ready to welcome the world.

"The good news would have been to have these stadiums by December 2013 and not March 2014 but the good news is still that we can work," he added.