Qatars bid to host the tournament was accepted in December 2010 in a decision that has since sparked much controversy.
Allegations of bribery emerged less than a year after the right to stage the World Cup was awarded to Qatar, while concerns over the extreme heat in the country during the months of June and July - when the competition is traditionally held - have led to calls for the tournament to be moved, with November and January touted as possible starting dates.
Additionally, human rights group Amnesty International has previously called for FIFA to intervene following reports of mistreatment of Nepalese migrant workers at World Cup construction projects in the Arab state.
Earlier this week, Blatter expressed his satisfaction at proposed labour law reforms in the Middle Eastern country.
However, he has now conceded that the decision to allow Qatar to host the event was a misguided one, citing the climate as his primary concern.
Speaking to Swiss TV channel RTS, Blatter said: Of course, it was a mistake. You know, one makes a lot of mistakes in life.
The technical report indicated clearly that it was too hot in summer, but despite that the executive committee decided with quite a big majority that the tournament would be in Qatar.