"Nothing is certain but I doubt I will be coaching (Japan) after 2006," the Brazilian was quoted by Japan's Nikkan Sports daily.
"Like I've said before, I still feel I can do a job for Japanese football. But I won't accept any offers from J-League clubs."
Zico, who was talking to Japanese reporters in Budapest, where Japan play Hungary in a friendly at the weekend, said that he had no interest in coaching Brazil.
"I don't want to coach another national team. Brazil? That's the one job I definitely won't do," said the 51-year-old, who scored 54 goals in 78 games for Brazil.
Zico has faced intense criticism after a string of poor performances since taking charge of Japan after the 2002 World Cup.
Disenchantment among Japan fans culminated in a public protest calling for his dismissal after a lucky 1-0 win over Oman in their opening 2006 qualifier in February.
