The France midfielder has expressed his pleasure at securing a move to ‘the Premier League’ and is ready for the challenge of keeping the Hammers in the top division.
“I am very happy to be here at West Ham,” Diarra told the official site.
“Everything is signed now which is good and I am excited to be here at this club and to be playing for them in the Premier League.
“I know a lot about West Ham as a club and when I knew they were interested in signing me, I was very happy and knew it would be a good choice for me.
“We are a Premier League club and I know of players who were here before like Paolo Di Canio and Scott Parker, but of the players now in the team, I know Guy [Demel], Mo [Diame] and of course, Modibo Maiga, who played in the French league last year.
“The club has just been promoted and I am looking forward to a good challenge with the team ahead. I see this as my chance in the Premier League to do well with West Ham. I hope that my experience can help and the fans will see me give my all in the matches.”