West Ham have announced the club-record signing of Toulouse defender Issa Diop on a five-year contract.
The 21-year-old centre-back joins the Hammers for an undisclosed fee, reported to be £22million.
"I am very happy to sign for such a historic English club, and I hope to show my best here," said the France Under-21 international.
"I am a very ambitious player and West Ham is a very ambitious club, as we've seen with the appointment of the new coach. I hope to help the team win lots of games and make the fans happy."
New boss Manuel Pellegrini has already brought in Fulham full-back Ryan Fredericks this summer as he attempts to bolster the club's defensive ranks.
The 59-year-old, who previously worked with new Hammers boss Manuel Pellegrini at Malaga, has signed a three-year contract.Read the full story ›
Javier Hernandez has refused to commit his future to West Ham after the arrival of new manager Manuel Pellegrini.
Hernandez signed a three-year Hammers contract last summer as he completed a £16million move from Bundesliga outfit Bayer Leverkusen.
But the 29-year-old striker lost his first team place towards the end of the season when he was sparingly used by former boss David Moyes, and it has been widely reported that he could leave the Premier League club this summer.
"Of course I am a West Ham player still, but we'll see," Hernandez replied when asked about his future at a press conference in Los Angeles ahead of Mexico's friendly against Wales on Tuesday morning.
"Right now what can I tell you? I'm glad there's a new manager? I'm sad there's a new manager?
"It's not the moment to speak about this. My mind is 100 per cent on the World Cup."
Asked if Pellegrini - who led Manchester City to a Premier League and Capital One Cup double in 2014 - was a good appointment by West Ham, Hernandez replied: "I don't know."
West Ham have confirmed defenders James Collins and Patrice Evra will leave the club when their contracts expire on June 30.
Centre-back Collins, who will be 35 in August, made 214 appearances over two spells with the Irons, while Frenchman Evra, 37, signed a short-term deal in February and played five times.
West Ham joint-chairmen David Sullivan and David Gold said in a statement on the club's website: "We would like to place on record our sincere thanks for the outstanding service James has given West Ham United down the years."
Manuel Pellegrini has signed a three-year contract to become West Ham's new manager.
The former Real Madrid and Manchester City boss succeeds David Moyes, having left Chinese Super League club Hebei China Fortune over the weekend.
Joint-chairman David Sullivan hailed Pellegrini's track record of winning the Premier League title with City as crucial to his chances of ushering in a new era of success at the London Stadium.
"I am delighted to welcome Manuel Pellegrini to West Ham United," Sullivan said on the club's website. "He is one of the world's most respected football coaches and we look forward to working with him.
"It was important that we appointed someone with knowledge and experience of the Premier League, who already has an understanding - not only of the teams and players we face - but of West Ham United and our ambitions.
"Manuel brings a reputation for attacking football and getting the best out of his players. We believe he will attract new talent to the London Stadium as well as improving the current squad.
"Above all, he is a winner, who knows what it takes to succeed at the highest level and is driven to continue that success. Manuel is the first West Ham United manager to have a Premier League title on his CV, and we believe that his experience, quality and proven record of taking teams forward quickly will ensure that he is successful here."
Manuel Pellegrini's path to West Ham appears clearer after he was released by Hebei China Fortune.
The 64-year-old former Manchester City boss has been heavily linked with becoming David Moyes' successor at the London Stadium.
And, in a statement on their Weibo account on Saturday, Hebei said: "We have reached an agreement with Manuel Pellegrini that he will no longer serve as team manager.
"Here, the club would like to express its sincere gratitude to Mr Pellegrini for his contributions and we wish him well in his future work life."
David Moyes has left West Ham United after six months in charge the club has announced.Read the full story ›
Mikel Arteta is close to becoming the new Arsenal manager after positives talks with the club according to today's rumours.Read the full story ›
Everton boss Sam Allardyce's future remains clear after his side limped to defeat away to Moyes' West HamRead the full story ›
West Ham and Manchester United played out a dull goalless draw at the London StadiumRead the full story ›