The Super Eagles face Tanzania in their opening Group C game on Tuesday, and the Malian coach urged his players to put behind them the disappointment of failing to reach the World Cup playoffs following defeat by the Democratic Republic of Congo in November.
"We prefer to stay focused at all times. I told the players to concentrate on themselves and on our development project. This is the most important thing we have," Chelle told a press conference.
"We are our first opponent, we need to focus on ourselves and take out outside noise. Of course, the World Cup miss is painful.
"We are here to win this first game. We have a tournament to play and we are here to be ambitious. I don’t have time to think about what happened before. I prefer to stay focused on what is happening right now."
Nigeria are struggling in defence due to injuries and the retirement of veteran William Troost-Ekong before the AFCON, but the 48-year-old coach expressed full confidence in his squad.
The 2023 Nations Cup runners-up will also play Tunisia on December 27th and Uganda three days later in the group stage.