The legendary Italian coach has taken over as the Selecao's first foreign boss and believes that the team are capable of winning a sixth World Cup in North America next year if everybody is united behind the side.
Ancelotti said: "It's the best national team in the world. That's not just my opinion, it's the five stars on their shirts.
"No other national team can match them. Now I've got the challenge of winning the sixth. I fully accept the challenge of bringing the sixth World Cup to Brazil, but to do so we need the whole country to be behind us.
"Brazil has to get behind the national team, the players need to feel supported, they need to be humble and stick together. Without humility, there's not much you can do.
"The World Cup is different from any club title. It's a feeling of having a country behind you, and that's why it's always appealed to me. I'm here to make Brazil champions again, I accept that and I'm convinced we can do it."
Ancelotti will link up with forward Vinicius Jr - who he managed at Real Madrid - in his new job and is convinced that he can get the best out of a player who has flattered to deceive since making his international debut in 2019.
He said: "He is extraordinary, fantastic, hardworking, a fighter like few others.
"The Brazilian player is very fond of the national team, and that can affect his natural thinking, putting a lot of pressure on him to do well, which doesn't allow him to make mistakes. I am convinced that he will give his best for the national team. He is one of the best in the world. He is always there.
"His best will soon come out."