Ronaldo got the news that his transfer to Real had been confirmed after being out clubbing all night in Los Angeles where he is on holiday.
Speaking from his hotel room, Ronaldo told The Sun: "It's flattering when two of the top teams in the world want you to play for them.
"Now I can look forward to Real Madrid and a new stage in my career. I learned of the deal here in LA and heard from my people that United had accepted."
Ronaldo has been troubled by a hernia injury but said: "I do not require surgery. The hernia is nothing to worry about."