But he has conceded he will have to off-load before he can bring in new blood during the current window - with around £3.5million likely to be recouped from the expected sale of midfielder Craig Gardner to Birmingham.
When asked if he was looking to sign a striker, O'Neill told Sky Sports: "We are not looking at players at this minute because we have to sell.
"Do I have to sell to buy? We wouldn't be the only club in that position."
O'Neill has faith in his current players to deliver the necessary firepower to sustain a challenge for honours.
Villa have failed to score in their last three league games, with Sky Sports analyst Jamie Redknapp claiming that striker Gabriel Agbonlahor looked short of confidence against West Ham at the weekend.
But O'Neill is backing the England player and his team-mates to start delivering the goods in front of goal.
O'Neill said: "I didn't hear the comments (from Redknapp). The only onus is on the team as a whole to get goals and not just one particular player.
"If you look at Gabby this season, he has held his end up reasonably well in terms of goals and performances."
Next up for Villa is the second leg of the Carling Cup semi-final against Blackburn.
Villa take a 1-0 lead into the home leg, and O'Neill is urging his players to adapt a "positive mindset" to ensure there are no slip-ups.
Villa will progress to their first major final for ten years if they repeat Sunday's goalless draw against the Hammers after triumphing 1-0 in the first leg at Ewood Park last Thursday.
But O'Neill is determined his players will not adopt a negative approach and rest on their laurels against Sam Allardyce's side.
"We have got to approach the game on its own merit and try and win the game from that viewpoint," he said.
"I don't think we could be thinking about having any other approach because it takes only a second to get a goal and, if Blackburn score early on, you are back to level anyway.
"Any advantage can be taken away in seconds. We must have a positive approach, absolutely, and forget the first leg in effect.
"I also think Blackburn would have taken great heart from the fact that decisions went their way at Ewood Park.
"They could have been in more serious trouble at half-time in that particular match. They came out very strongly in the second half as we expected and yet we had some chances ourselves.
"The game tomorrow night will be very tight."
O'Neill is aware what a Wembley final would mean to the club and the players.
He said: "There is no doubt, it is a very important game. We have come this far. I don't want to throw it away and we want to give everything we have and I know that is the one thing we will do.
"On the day, we may not get the luck to carry us through, I don't know, but it won't be through lack of trying.
"The players are buoyant and they can get even better as players and as a team. There is plenty of confidence about the team and we are ready to go."
Striker John Carew is Villa's only new injury doubt with a knee injury suffered in training on Monday.
But the Norway international has been confined chiefly to the bench in recent games and O'Neill is likely to retain the team which won at Ewood Park.
That will mean number two keeper Brad Guzan, who has played in the majority of the cup games this season, again taking over from Brad Friedel.