The Brazilian daily Folha de Sao Paulo reported Tuesday that a study by a FIFA consultant on the stadium construction or renovation program at the 12 World Cup 2014 stadiums pointed to various degrees "of risk" for arenas in Manaus, Cuiaba, Porto Alegre, Curitiba and Sao Paulo and no "margin for problems" at the stadium in the northeastern city of Natal because of a "tight schedule."

In a statement, FIFA said the document cited by Folha was an internal monitoring report developed at the end of April for stadium experts.

"This document is for the stadium experts and can be easily misinterpreted without the respective background information on the various evaluation criteria and parameters," it noted. "What is important though is the significant progress which has been made at the venues for the FIFA Confederations Cup Brazil 2013, particularly Recife, Rio de Janeiro and Salvador."

The Confederations Cup, a dress rehearsal for the World Cup, will be held in Rio de Janeiro, Brasilia, Belo Horizonte and Fortaleza. Recife and Salvador could be added depending on progress on the work.