The Blancos president insists everything possible will be done to extend the Portuguese superstar's current contract
The Blancos attacker has scored 34 times with one game to go in the Liga season and was crucial in seeing the side reach the Champions League semi-final stage for the third conseutive campaign, finishing as the tournament's top scorer.
Having expressed his unhappiness earlier in the season and with compatriot Jose Mourinho leaving the club, Ronaldo has been linked with a summer departure from Santiago Bernabeu, but Perez is adamant that even an offer as large as €1 billion would not convince the Spanish club to sell their prized asset.
"I will do everything in my power to renew his contract," he told Cadena Cope. "He has two years left on his contract, he is the best player in the world and we would like to give a boost to the team by keeping him as a leader and an emblem.
"I would not sell him for €1bn. We are not a selling club. He is a winner and he wants to win titles and Real Madrid are the right club for it.
"When he said he was sad, he talked to me and I told him I would do everything possible for him to be happy."
Real Madrid have secured second spot in La Liga and will play their final game of the season - and Jose Mourinho's last as head coach - against Osasuna on Saturday.
The club president said of the outgoing Portuguese: "I give him a B+ for his time at Madrid - we have been a bit annoyed by some results. As time goes by, though, we realise that the work of Mourinho has been very positive."
"People are what they are. He lives all with so much passion and so much demand that sometimes things happen [regarding fallouts with players]."