Balotelli left England in January 2013 when Manchester City sold him to AC Milan, but the 24-year-old endured a difficult time in Milan, where he was subjected to racial abuse by opposing fans.

After completing his switch to Anfield on a three-year contract worth a reported �90,000 a week, which includes an option for a further year, Balotelli conceded he had been wrong to ever leave England.

"I'm happy to be back because I left England and it was a mistake. I wanted to go to Italy, but I realised it was a mistake," Balotelli told Liverpool's website.

"English football is generally better. English football is beautiful."

Liverpool did not complete the transfer in time for Balotelli to play in their 3-1 loss at City on Monday, but he attended the match and sat in the directors' box wearing a dark top and a beanie hat.

He had earlier completed a one-on-one training session with Liverpool's head of conditioning and fitness, Ryland Morgans, at the club's Melwood base.

Balotelli earned a reputation as a troublemaker during his three-year stint at City, where his antics included setting fireworks off in his own house and brawling with then-coach Roberto Mancini.

Speaking before his side's defeat at the Etihad Stadium, Liverpool manager Brendan Rodgers admitted that Balotelli's signing represented something of a gamble.

"Mario is at a stage in his career where this might be his last chance," the Northern Irishman told Sky Sports.

"He needs to settle down and show maturity, but I have worked with loads of players like that.

"He has huge potential, but he needs to come here and be consistent and if he can do that then we have one hell of a player.

"We have strong family values and behaviour is very important here. We believe we can improve his game and consistency in his game."

Asked what he expected from Balotelli, Rodgers joked: "Trouble!"

- Champions League ambition -

Having won the Champions League with Inter Milan in 2010, Balotelli said he wanted to repeat the feat with Liverpool on the Reds' return to Europe's elite club competition this season.

"I want to win another Champions League for sure, because the Champions League wasn't all mine -- I was in a team," he added.

"I always start a competition wanting to win it. I want to take this team to the Champions League."

Balotelli received a hostile reception from Liverpool fans during his visits to Anfield while with City, but he was given a warm welcome by supporters who gathered outside the club's training ground to catch a glimpse of the striker.

"I didn't expect it because whenever I played against Liverpool, the fans weren't nice with me, but that's normal -- it's football!" Balotelli said.

"Now that I play for Liverpool, I can see the expectation in people. They're very happy and that makes me very happy at the same time.

"Liverpool are one of the best teams here in England. The football is very good here. It's a great team with young players, and that's why I came here."

In light of Balotelli's reputation as a troublemaker, Rodgers is believed to have asked for the player's contract to include strict clauses about his behaviour on and off the pitch.

But the desire to land a top-class replacement for Luis Suarez, who was sold to Barcelona, persuaded Rodgers to sanction the deal for Balotelli, who won the Premier League and FA Cup during his time at City and also lifted the Italian title three times with Inter.

"This transfer represents outstanding value for the club and I think we have done a really smart piece of business here," Rodgers told the club website.