"Liverpool have given me the chance to show that at 32 I'm still one of the best defenders, and I will fight for that," said the centre-back, who has officially signed for the Reds after his contract expired with the former Premier League champions.
"These past two years of being 'part-time' have helped me refresh and be more hungry.
"I want to try and help Liverpool win trophies this season."
Toure leaves brother Yaya behind at the Etihad Stadium but he knew it was not an option for him to remain at the club.
"I haven't spoken to him yet really because he's been on holiday but he's going to be on his own there now," he added.
"I wish him the best but I knew I had to leave City. I've come next door and that's a great move for me."