Arena das Dunas' marketing director Arthur Couto revealed that the stadium still doesn't comply with the standards set by football's world governing body FIFA, reported Xinhua.
"We are conducting test events and will continue to work to make sure we meet FIFA's specifications," Couto said following the venue's first match between America de Natal and Confianca de Sergipe.
Pending work includes the addition of 10,000 provisional seats to lift capacity to 42,000 and urban planning projects to improve stadium access.
Arena das Dunas is the first of Brazil's six World Cup stadiums that were not used during last year's Confederations Cup.
Located in the northeastern state of Rio Grande do Norte, the venue will stage four World Cup matches in June and July.