FIFA Secretary General Jerome Valcke has acknowledged there is no back-up plan if the venue scheduled to host the opening game of the Confederations Cup isn't ready in time.
The National Stadium in Brasilia is set to stage the game between Brazil and Japan on June 15, but the date for its completion was pushed back a month to May 18 earlier this week.
Valcke says "that is a real problem because we don't have a `Plan B.'''
The tournament is a test event for the 2014 World Cup and runs through to June 30. It will also feature Spain, Mexico, Uruguay, Tahiti, Italy and Nigeria.
FIFA said on Tuesday that the "daily and on-site monitoring of the stadium construction works'' at the six Confederations Cup venues "will be intensified.''