President Barack Obama has admitted exchanging letters with the Iranian president, Hassan Rouhani, in a move which could set the stage for the first meeting between a U.S. and Iranian leader since Iran’s 1979 revolution.

It is hoped a meeting could lead to a solution in the row over Iran’s nuclear weapons programme, which Obama said is ‘larger than the Syrian crises’.

Foreign secretary William Hague is also said to be due to meet Mohammad Javad Zarif, Iran’s minister of foreign affairs, at the UN general assembly meeting in New York.

But Obama admitted that it would not be easy.

In a television interview aired on ABC News, on Sunday, when asked whether he and Rouhani had ‘reached out’ to each other, Obama confirmed that they had exchanged letters, the Guardian reports.

Obama said: ‘I have. And he’s reached out to me. We haven’t spoken directly…’

He added: ‘Negotiations with the Iranians is always difficult.

‘I think this new president is not going to suddenly make it easy.’