The 35-year-old has expressed concern over the lack of progress in World Cup preparations, but stressed that the country's right to host the event is not at risk
Valcke has earned widespread criticism after stating that Brazil needed a "kick up the backside" to speed up preparations for the showpiece event.
Romario and Brazil's sports minister Aldo Rebelo are amongst those who have hit back at Valcke's comments, but Ronaldo has admitted to being worried about the slowness of preparations.
"His words may have been lost in translation," Ronaldo told TV Bandeirantes. "He has already apologised to the Brazilian people.
"His comments were unfortunate, but it does not mean he is not right. Brazil promised that the law about the World Cup would come into force a long time ago, while there are delays in terms of rebuilding our infrastructure.
"We are still late in a lot of things, but the Brazilian people must not be afraid.
"There is not the slightest chance that Brazil will not host the World Cup."