The 74-year-old Swiss, first elected president in 1998, is unlikely to be challenged when he seeks a fourth four-year term in office when his current tenure ends in 2011.
"I have not yet completed my mission as president of FIFA, I am motivated to go for another term," he told FIFA delegates at their 60th congress to a spontaneous round of applause.
"Thank you for your confidence. I would like to say we will go for it together. I am ready, you are ready," he added.
Asked later whether it would be his last term in a role observers say makes him sport's second-most powerful person after the president of the International Olympic Committee, he said: "I cannot say it will be the last one because I don't even know what will happen next year."
On the eve of the first World Cup finals to be held in Africa, Blatter did not deliver a passionate, electioneering-style address to delegates from 207 of FIFA's 208 member countries.
Instead he concentrated on the aim of world soccer's governing body to eradicate society's vices that blighted the sport, especially racism and discrimination.
"Violence, cheating, doping, betting, discrimination and racism, these are all in our game," he said.
"We have started to eliminate them, one is practically eliminated -- this is doping. But here in this World Cup in South Africa, and specifically through this Congress, we declare we are against discrimination.
"Never, never again should we have any problems on any football field or in a stadium concerning discrimination or racism."
The Congress also agreed to keep the Olympic soccer tournament as a competition for players aged 23 and under rather than lowering the age limit.
HAVELANGE'S VISION
With one day to go before the World Cup kicks off, Blatter said holding the finals in Africa completed the vision of former FIFA president Joao Havelange, who wanted to make football the global game when he became president in 1974.
"It was not easy, much has been said about it. But now the World Cup is here. This is touching the world," he said.
Irving Khosa, the chairman of South Africa's organising committee, backed Blatter's words when he said this World Cup would help bury the stereotypical image of Africa and a successful World Cup would prove the cynics wrong.
Blatter also said FIFA's finances had been affected by the worldwide economic downturn in 2008 but, with a turnover of more than a billion dollars a year, it was "comfortable".
As a result, Blatter confirmed each association would get a one-off bonus payment of an additional $250,000 next year, on top of their annual grant of the same amount from FIFA.
That decision was taken last month by FIFA's executive committee, which also agreed each of the six confederations should be given a one-off payment of $2.5 million next year.
Blatter also reminded delegates of his opposition to technology in the game. "Society is not perfect, football is not perfect, it must retain its human face," he said.