Manchester City strengthened their injury-hit defence on Thursday by signing Swiss international Manuel Akanji on a five-year deal from Borussia Dortmund.

Akanji will provide the Premier League champions with extra defensive depth after recent injuries to centre-backs Aymeric Laporte and Nathan Ake.

"I am delighted to be here, and can't wait to get started," Akanji, who cost City a reported £17 million ($19.7 million) told the club's website.

"City have been one of the best teams in Europe over the last few seasons. 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."

The 27-year-old spent four-and-a-half seasons with Dortmund after joining from Basel in 2018.

Akanji is City's fifth summer signing after former Dortmund team-mate Erling Haaland, Kalvin Phillips, Sergio Gomez and Stefan Ortega Moreno.

"We have been impressed with his (Akanji) 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," said Manchester City's director of Football Txiki Begiristain.

"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."

Both Akanji and Haaland could face their former club on September 14, with Dortmund due to play City at the Etihad Stadium in the Champions League group stage.