In an interview to be published in Portugal on Thursday, while repeating his previously-stated desire to play for Real, Ronaldo has also confirmed he will stay with United for another season at least.
He goes on to praise Sir Alex Ferguson, who flew to Portugal just after Euro 2008 for talks with Ronaldo.
Ferguson was always confident he would win the battle to keep Ronaldo but the news still represents a major coup for the Scot, who lost trusted assistant Carlos Queiroz, a close friend of the 23-year-old, to the Portugal national job last month.
Ronaldo said: "Sir Alex Ferguson heard my arguments, I heard his and, in fact, it was settled that the best for both parties would be for me to stay.
"Therefore, I can confirm that, next season, I will play for Manchester United.
"Before rumours emerge saying that I will play against my will, I want to make this clear - whoever says or writes that is lying.
"I will play for Manchester with all my heart and soul. I will fight and honour that shirt with the same commitment and dedication as always."
But he repeated that his dream of playing for Real remains and has not closed the door on a future move to the Spanish giants.
He explained: "I knew Real Madrid were interested in signing me and that they had allegedly made a very high offer to Manchester United.
"My desire was, for some time, that Manchester had accepted my transfer to Madrid.
"Saying otherwise would be to trick people and my own consciousness."
