Blatter directed the apology specifically to England and Mexico whose teams were the victims of referee errors. England was disallowed a legitimate tying goal against Germany and Argentina was granted a goal against Mexico that proved to be offsides.
Both team eventually lost the matches and were knocked out of the tournament being played in South Africa. In both cases, video replay could have corrected the wrong decision by the refs.
"Naturally we deplore when you see the evidence of refereeing mistakes," said Blatter, according to the Associate Press. He added that officials from both teams accepted his apology.
"The English said 'thank you.' The Mexicans, they just go with the head," Blatter said, suggesting they nodded. "I understand that they are not happy. It was not a five-star game for refereeing."
FIFA has long resisted calls for the use of technology during matches. Today, the FIFA honcho said it would be "nonsense" not to discuss those changes.
"Naturally we will take on board again the discussion about technology. Something has to be changed," he said, while adding that no modifications would take place during this World Cup.
The issue of video replay will be reopened at a meeting of FIFA's rule-making panel in Wales next month.
Blatter did not mention the refeering errors that cost Team USA two goals in separate games -- goals that did not matter in the long run because the USA won the games and advanced to the knock out round where they were beaten by Ghana 2-1 in extra time.
Blatter, who has attended 20 matches, said that game was the most memorable of the tournament so far.