Brazil's Arena da Baixada "does not have a moment to lose" if it is to make the year-end construction deadline for 2014 World Cup stadiums, football's governing body FIFA has warned.
The stadium in the southern city of Curitiba is the least advanced of Brazil's 12 World Cup venues with redevelopment work only 80 percent complete, reports Xinhua.
"It's one of the stadiums where there is still work to be done and it's being permanently monitored by the local organising committee," FIFA general secretary Jerome Valcke told the media on Thursday.
"We have people going there regularly to meet with those responsible for the stadium, the surface and the surrounding area. There's not a moment to lose if the stadium is to be ready for the World Cup."
Arena da Baixada will host four matches during the June 12 to July 13 tournament.
Work on the stadium was halted earlier this month by a labour court judge, who claimed the venue posed a safety risk to workers.
The ban was lifted five days later.
Valcke reiterated there would be no flexibility to the year-end cut-off for stadium construction work.
"The question isn't whether the stadiums will be ready or not," he said. "They will be ready. The question is whether they will be ready to be equipped with the necessary facilities. For this reason work needs to be speeded up."
FIFA also warned that the surface of Brasilia's Mane Garrincha stadium is not yet up to World Cup standard.
Brazil and Chelsea defender David Luiz was among those to criticise the pitch's unevenness before Brazil's 6-0 friendly victory over Australia at the venue last month.
"The quality of the surface in Brasilia isn't what it should be," Valcke said. "We hope it improves. It's not a criticism but a fact."
"We are now in October and the World Cup will be in 245 days. We have plenty of time to make sure everything is right by then," he said.