A ¦pound;10.46million (12.5million euro) move has appeared on the cards for several weeks now, and the 21-year-old Hamburg player told Bild magazine it will be wrapped up in the coming days.
"I am going to sign on (for City) before leaving for the World Cup and the deal will be completed," he said.
"It has been decided that I am moving there."
Boateng confirmed City manager Roberto Mancini had visited him in Hamburg and talked him into the move.
"He came with two representatives to Hamburg and we chatted for one or two hours," said Boateng.
"He convinced me to make the transfer. He believes that I will definitely need a few months to get settled in once in England, but that he sees so much potential in me that he will improve me.
"Even if many people say that I am going to struggle to make the breakthrough, I am confident that I will.
"I am not afraid of anybody."