Ireland have been drawn in a tough qualifying group with Germany, Poland, Scotland, Georgia and Gibraltar.
Keane and boss Martin O'Neill have so far overseen a 3-0 home victory over Latvia and a goalless draw in Poland in November. And on Wednesday they face their third friendly against Serbia at the Aviva Stadium.
And Keane admits he is looking forward to the real battle of qualification starting against Georgia in September.
Keane said: "I am enjoying working with Martin and (goalkeeping coach) Seamus McDonagh and all the rest of the staff and the players.
"But we know, obviously, the bigger tests are to come. If we couldn't have enjoyed the last few months, there's something wrong.
"We understand it will get serious in the next few months, and even with these friendlies - people have been very polite and give us good backing, but we are here to get results.
"We are under no illusions about that, Martin and myself. We have been in the game long enough.
"It's well and good getting pats on the back, but we are here to win football matches, and that will be tough. But we are ready for it.
"I am looking forward to the games, very tough games for different reasons. But I always said to the players and every time I have been involved with Ireland, you have got to believe you can go and win every football match, and hopefully that's what we can bring to the group.
"It's a very tough group, but one we're looking forward to. Everybody keeps saying that we're going to be up against some good teams, but we're a good team so, no, roll on September, we'll be ready."
Among the players to arrive for Ireland training in Monday was Hull midfielder David Meyler who has been on the front and back pages in the last couple of days following his brush with Newcastle manager Alan Pardew.
However, Keane refused to be drawn into the row when asked about Pardew's behaviour.
He said: "I have no comment on it, I have no real interest. It's none of my business."
Pressed on how Meyler was, Keane added: "He's fine. You have seen him training, he's having a good season for Hull and it's good to have him involved.
"Obviously I know him from my days at Sunderland, I took him over from Cork City. Meyler's a good lad and it's nice to have him back involved in the squad.
"There's an opportunity there for him, and what's good for Meyler is he is back in the Hull team, he's playing regularly and that will always give you a chance at international level."