West Ham have completed the £29.8m signing of Kurt Zouma from Chelsea on a four-year deal.
The 26-year-old centre-back has signed a contract until the summer of 2025 after undergoing a medical on Thursday.
Sky Sports News previously reported that West Ham were keen to add defensive reinforcements and had targeted Zouma, who had fallen out of favour at Chelsea under Thomas Tuchel.
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"I'm very happy and very proud," Zouma told West Ham's official website.
"My conversation with the manager went very fast. I just felt like he really wanted me to come and join the team, especially a good team that's started the season very, very well.
"With the great season that West Ham had last year, that gave the team a lot of confidence to improve this year - and I want to help the team do that."
Zouma won two Premier League titles, the Champions League and the League Cup during seven-and-a-half years at Stamford Bridge.
The France international has eight caps for his country and has been called up to Didier Deschamps' squad for next month's World Cup qualifiers.
West Ham manager David Moyes added: "I am delighted to welcome Kurt to West Ham United. He is a player we have tracked for some time, and we have taken great care and diligence to make the transfer happen. He was always our first choice and I am very happy that he is now our player.
"Kurt will join a squad full of players who are hungry and ambitious. He will provide competition to our squad. He is a strong, powerful player with great experience in the Premier League while he is also at a good age for a centre-back.
"Kurt has enjoyed great success at Chelsea and I can see that he is determined to continue being successful here at the London Stadium. Myself, the coaching staff and players are all looking forward to working with him and we wish him all the very best in his career with us."
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