"The issue has already been talked about," the Portugal forward told a news conference when asked about his contract situation after training.
"I won't talk about my renewal any more," added the 27-year-old whose deal with La Liga champions Real runs until June 2015. "It's not the most important thing, the important thing is to win our next games.
"We are fighting for La Liga, the Copa del Rey and the Champions League - the important thing is to be united. I am feeling very comfortable at the club and I hope to give the best of me for this shirt as I always have done."
Ronaldo, the world's most expensive player, raised eyebrows earlier this season when he said he was feeling sad "for professional reasons" and that Real officials knew why.
He did not explain further, leading to media speculation he was unhappy with the terms of his deal and wanted more money.
Some reports have suggested Ronaldo might be lured to a big-spending club like Paris St Germain or that he may return to Manchester United who sold him to Real for a record fee of £80 million in 2009.
Real play United in the last 16 of the Champions League, with the first leg in Madrid on February 13 and the return in Manchester on March 5.
"I have feelings of strong friendship, a lot of warmth," Ronaldo said of the tie. "It's a team that had a big influence on my career.
"The people know me well. I have a lot of friends, people who have a place in my heart - but now I defend the colours of Real Madrid. The feeling will be a slightly sad one but I want to win and score, give my absolute best."
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