The 23 year old England midfielder has 14 months remaining on his present deal with Everton and is yet to agree fresh terms to extend his stay at Goodison Park, leading to speculation he could leave in the summer.
"I spoke to Ross several weeks ago and he mentioned his ambition, Champions League, and I told him I have the same ambition," Koeman said.
"We're going in a good direction and he is a key player, he is a kid of the club, a kid of the town and in my opinion, there is no better place for him to continue.
"I think it's a normal ambition for players, every player and manager wants to play in the Champions League.
"Our next step is to play in Europe, it may be difficult, if we finish fifth or sixth that will be perfect because you don't play any pre-qualification games for Europe."