The NHS in England is facing a funding gap of about 2 per cent (£2 billion) of its budget, for the next financial year, the BBC reported.
Senior health sources told the BBC growing costs would outstrip the money the NHS received from April 2015.
The NHS’s budget in England for 2015 has been set at about £100bn.
Health secretary Jeremy Hunt is involved in Whitehall talks on how to plug the gap.
The Department of Health said it was “confident” it would “make the savings necessary to meet rising demand”.
Due to the government’s plan to minimise the UK deficit, the NHS has been suffering from prolonged budget freeze.
Several factors including rise in population have led to increasing demand on NHS services.
In a statement, the Department of Health said: “The NHS is on track to make £20bn savings this parliament and we are confident that it will continue to make the savings necessary to meet rising demand.”
Meanwhile, Hunt said he was confident in the sustainability of the NHS.
But some health chiefs told the BBC the sums for the financial year beginning next April did not add up.