Akanji has 41 caps for Switzerland and played a key role in their qualification for the World Cup.

"I am delighted to be here and can't wait to get started. City have been one of the best teams in Europe over the last few seasons," he said.

"They are brilliant to watch, play an exciting brand of football and compete for trophies year in, year out, so coming here feels like the perfect next step in my career.

"Pep Guardiola is an exceptional manager and this is an exceptional squad of players, so this is an exciting opportunity for me.

"I am really looking forward to testing myself in the Premier League and I will do everything I can to help this club be successful."

Akanji, who began his career with FC Basel, links up with former Dortmund team-mate Erling Haaland following his move to City earlier this summer.

He is the fifth signing Guardiola has made during this transfer window as City look to win a third successive Premier League title and a first Champions League trophy.

City's director of football Txiki Begiristain said: "Manuel has plenty of experience playing at the top level of European football and we are confident he will be a valuable addition to our squad.

"We have been impressed with his performances during his time at Dortmund, where he has developed into a very good defender and one who is ready to perform in both the Premier League and Champions League.

"He has everything we want in a centre-back. He is strong, quick, comfortable in possession, has an excellent passing range and he will complement the other defenders in this team and our style of play."