O'Neill admits it won't be easy adding to his squad this month but remains steadfastly determined to do so.
"We are looking to improve our squad if we can this month, although it will not be easy," he told the Birmingham Mail.
"Players people are mentioning I'm quite sure are in the thoughts of clubs of a similar ilk to ourselves.
"But it doesn't mean we won't be trying to do something."
O'Neill says he will not allow Villa's season to falter by not strengthening.
Villa have a squad of 23 players, including three goalkeepers and two players without any first-team experience.
O'Neill said: "We don't have the numbers that you would normally associate with a Premiership side.
"We have done really great so far, now you don't want the season just to level out.
"It's the time of year when we can strengthen and we're in there looking at players."