The 86-year-old was in charge of world football’s governing body when the Gulf state were awarded in 2010.
Qatar has been criticised for its stance on same-sex marriages, human rights record and treatment of migrant workers.
The tournament starts on November 20 with the hosts taking on Ecuador in the opening game, played at the Al Bayt Stadium in Al Khor.
It is the first World Cup finals in the tournament’s 92-year history to be played during winter in the Northern Hemisphere, disrupting the club game across Europe.
Blatter spoke to Swiss newspaper group Tamedia in his first major interview since being acquitted with Michel Platini in July of financial misconduct at FIFA after a trial at federal criminal court.
"It is too small of a country. Football and the World Cup are too big for it," he said.
"It was a bad choice. And I was responsible for that as president at the time.”