Football's governing body FIFA said it is still seeking guarantees that temporary structures will be built in time for the opening World Cup match at Sao Paulo's Itaquerao stadium on June 12.

In a press conference in Rio de Janeiro on Thursday, FIFA secretary general Jerome Valcke admitted time was running out for a funding deal to be struck between local government officials and developer Odebrecht.

"Tomorrow we will have a solution. I am confident about Sao Paulo because they have a great developer in Odebrecht, which will deliver everything," Valcke said.

Brazil's sports minister Aldo Rebelo said the federal government was involved in the discussions.

"We are working so that the prefecture, the state government and the owner of the stadium can reach an agreement," Rebelo said.

The Itaquerao, which will host six World Cup matches, has been given an April 15 deadline for the completion of construction work.

Among the stadium's temporary structures are 20,000 seats which raise the venue's capacity to 68,000.