The Real Madrid president has vowed to pay the Portuguese whatever it takes to make him stay at the club beyond 2015, when his current deal expires.
The Portuguese forward's current deal expires in 2015 but the La Liga champion's hopes for an extension were dealt a blow when he admitted that he was unhappy at the club in September.
The 28-year-old has since been linked with a return to Manchester United, whom he left in 2009 to join the Spanish capital club, but Perez remains confident of keeping his star man at the Santiago Bernabeu.
"Keep calm, we are going to renew with Cristiano Ronaldo. The club are going to pay him," he told Blancos fans at a meeting.
Jose Mourinho's side faces Borussia Dortmund in a European semifinal first leg in midweek and has a Copa del Rey final with Atletico Madrid approaching and Perez says he is happy with the way things are going.
"Real Madrid are having a great month with the Champions League and the Copa del Rey final," he continued. "Being the president of this club is difficult but so is being the coach. We must learn to live with it. We can discuss it between us, but we have to stay together.
"Criticism helps us."
Cesc Fabregas' late goal against Levante ensured that Madrid remains 13 points behind Barcelona with six games to go - an unrealistic mountain to climb if the club is to retain its Primera Division crown.