The company declined to comment on reports at the weekend that top executives from the two companies have met for "preliminary talks" but have yet to agree terms.
A SmithKline spokesman said: "We are a strong independent company. We don't need a merger."
The reports suggested that an outline discussion would value SmithKline at pounds 11.50 a share compared to the current share price of pounds 8.37. A special dividend payment to shareholders was also suggested.
One suggested rationale behind the deal was that it could prevent a counter-offer from Glaxo-Wellcome, the UK drugs group whose merger talks with SmithKline collapsed in acrimonious circumstances last year.
Glaxo is still thought to be keen on a deal with SmithKline, with industry experts suggesting that the retirement of Jan Leschly, SmithKline's chief executive next year, could trigger a fresh move by Glaxo's chairman, Sir Richard Sykes.
Novartis was formed in 1996 following the merger of two Swiss companies Sandoz and Ciba Geigy in a deal value at pounds 65bn.
Recent comments from Mr Leschly suggest he is happy with the way that SmithKline is trading and feels no pressing need for a major deal.