FIFA secretary general Jerome Valcke has warned that delays in completing the stadium in Sao Paulo could result in the city being stripped of hosting 2014 World Cup matches.
Sao Paulo is scheduled to host the opening game, as well as others, but Valcke says organizers "have to speed up."
The Frenchman says "it's not a threat" but "until the first minute of the ticket sales" on Aug. 1 there can be changes in choosing host venues.
Engineers in charge of the stadium construction said last week it will be not ready by December as FIFA wants.
Valcke said FIFA won't tolerate delays with the 12 World Cup stadiums. Only two of the six venues for the Confederations Cup — a warm-up tournament this year — were completed on schedule.