Pep Guardiola's side agreed to a fee of STG40 million ($A73 million) for the 25-year-old, who signed a five-year deal to become the club's second addition of the summer transfer window.

"City have been the best side in over the course of the last decade," Ake said.

"This is a top side full of world-class players. Everywhere you look in this squad there are big names with international pedigree.

"Pep is a manager admired across the world - what he's done in the game speaks for itself. The success he's had is unbelievable and the style of football he plays really appeals to me."

City signed Valencia winger Ferran Torres on Tuesday.

City was dethroned as Premier League champions by Liverpool in the pandemic-disrupted campaign that finished last month.

City remains in contention for the Champions League this month, which Ake is not eligible for.

"The new season is due to begin in September.

"I know I'm going to have to work hard to get into the side, but that's what I'm here to do," Ake said.

"I'll do whatever I can to make an impact and help the team win silverware."

Australian Associated Press