Chelsea are believed to have paid around 30 million pounds for the Ukrainian, arguably the most deadly finisher in European football.

"I am here for the challenge and the excitement of playing in the Premier League. I am going from one big club to another and joining a team of champions," Shevchenko told the London club's official website chelseafc.com

"There is a right moment to join a football club and I think I have arrived here at the perfect time.

"The Champions League has to be a realistic target for next season but it is not just about the Champions League. Chelsea is going for their third Premiership as well and I like the club's mentality of wanting to win every game they play.

"I have followed Mr (Jose) Mourinho's career carefully for the last few years and have been hugely impressed with the way he manages.

"He puts team ethic before individual expression which is the way I believe great teams are created," said the Ukrainian striker.

"Had money been my motivation for coming, I would probably have stayed in Milan.

"I am pleased that Chelsea managed to conclude everything before the World Cup -- I can go to Germany with a clear mind and proud to be a Chelsea player."

Shevchenko became Chelsea's third signing of the summer following the capture of Germany captain Michael Ballack, on a free transfer from Bayern Munich, and Salomon Kalou, who has come from Dutch club Feyenoord for an undisclosed fee.

Kalou, 20, acknowledged that he may have to be patient about getting first team opportunities given the depth of talent available to manager Jose Mourinho.

But the Ivory Coast-born forward, who scored at a rate of more than one goal for every two games over the last two seasons, said he is ready to fit in wherever Mourinho opts to deploy him.

"I will play wherever the trainer tells me to play, I do not complain. I just try to do my best every game," Kalou said.

"I want to be in a team where I can be a better player, and will do my best to reach the top here.

"I do not expect to play in any position, I will just play where they put me and am going to do my best."

He added: "It was only my second season with Feyenoord and I scored 15 goals, and for someone who plays on the left side that is not too bad.

"But you can always do better and you do not have to be satisfied with what you do. You have to keep working."

Kalou was voted the best young talent in Holland in 2004/05 and has applied for Dutch citizenship, although his application was not processed in time for him to represent the Netherlands in the World Cup this summer.

Chelsea chief executive Peter Kenyon believes the club have acquired a valuable asset for the long term.

"He has a great record of scoring goals," Kenyon said. "He is one of the bright young talents -- and I think that fits the bill very much."

Kalou's arrival signals the end of England under-21 striker Carlton Cole's time at Chelsea. Cole is set for a move to Tottenham or Premiership newcomers Reading and Icelandic forward Eidur Gudjohnsen could also be on his way out of Stamford Bridge before the end of the summer.