The 35-year-old has flourished in the States after joining LA Galaxy from Tottenham in 2011, scoring 68 goals in 102 appearances, reports Sky Sports.
Speaking ahead of Republic of Ireland's European Qualifier away to Gibraltar, Keane said he is still loving life in the States and has seen a huge improvement in standard since his arrival.
"The standard of the game, the quality of the coaching, the set up at the Galaxy - it's second to none," he told Sky Sports.
"As soon as you go into a different environment or set-up, you have to throw yourself into it, embrace the culture, knowing things are going to be a little bit different to what you are used to.
"I was very lucky at the very start that I had (David Beckham) Becks there. When it was frustrating at times, he was the one who explained it would get better and the difference between the first six months and now is absolutely incredible.
"Stevie (Gerrard) has been shocked with how professional everything is, how good the coaching is and how well they look after you."