Blatter spoke on Thursday in the Costa Rican capital, where he was attending the Under-17 Women's World Cup.
Blatter said FIFA could not take responsibility for the death of a worker last week at the stadium in Sao Paulo. Seven workers have been killed at World Cup venues, five in the last six months with work speeding to finish for the opening match in 10 weeks.
"Who is responsible for this?" he asked. "Is it FIFA? They are pointing at FIFA, and it's not true. It's basic to provide workers with safe conditions to do the work. We can't go and watch at every construction site."
A fourth stadium, already opened in Porto Alegre, has been hampered by a dispute about how to pay for temporary facilities for television, hospitality and security. Despite the problems, Blatter predicted the World Cup would be a success.
Also Read
"Brazil will be a well-done World Cup," he said. "Some of the delays is because there was no work for years. But we're on the way now to finishing the stadiums."
Brazil is spending about $3.5 billion on 12 stadiums, and the costs keep rising. Many related infrastructure projects promised for the World Cup like train lines, expanded airports and new roads have been put off or cancelled.