Cristiano Ronaldo has warned Barcelona that he will atone for his Nou Camp penalty miss in next week's semi-final decider at Old Trafford.

The Portuguese winger blazed a second-minute spot kick past the post as United and Barca fought out a goalless first leg draw, but he insists he will score when the teams reconvene in six days' time.

"Today I didn't score," he told Sky Sports. "No problem, now I'm going to score in Manchester. Nil-nil is a good result. Of course, if you score a goal it is better for us. We didn't score, but 0-0 is good.

"It was a tough game, Barcelona played very well and kept the ball a lot. But I think we defended very well and we played well too. I think 0-0 away is a good result."

Aside from Ronaldo's penalty miss - and the decision not to award a second spot kick for a foul by Rafael Marquez - the 23-year-old winger is still confident that United can book a berth against either Chelsea or Liverpool in Moscow.

"Now we're playing at home, and I think we're going to win," he said. "The team feels good confidence, we played very well, we play at home now and we have a great chance."