'We have a more experienced team and are the reigning champions,' said Ronaldo. 'It's time to kill or be killed. Whoever loses will exit the competition - and we don't want to lose.
'It will be a difficult game but I think Manchester United have a better team. They're a team with very experienced players but we also have our aces and great players.
'It will be a good game, a well-contested game, and the better team will triumph. It is going to be a titanic fight – Inter are top of Serie A which tells you immediately they are a good team who are going to give us a tough game.
'But we are playing well, which should give us confidence. We just have to be ready.'
Mourinho stoked up the fires ahead of the first leg in the San Siro tonight by claiming that United, if not afraid, carried such respect for Inter that they would play defensively in Milan.
Ferguson dismissed the idea, insisting United would be looking for a positive result to take back to Old Trafford, and his winger is eager to start the tie on the front foot.
'A good result is a win but if we draw it is not bad because Inter know it will be difficult to beat us in Manchester,' said Ronaldo. 'I have won the Champions League and want to repeat that very soon.'
Inter captain Javier Zanetti believes Manchester United are "one of the strongest teams in Europe", but insists the Italians will be able to compete with them tonight.
"I think we are up against a big team which is doing very well in the Premier League and in the Champions League, but I am confident that we can do it," he said.
"We are a very competitive team and this is a clash between two big teams who want to continue in the Champions League.
"We are up against one of the strongest teams in Europe. We respect Manchester a lot, but we are in condition to be able to do very well."