The US and Iranian presidents, Barack Obama and Hassan Rouhani, may meet at the United Nations in New York next week following an exchange of letters between the two leaders.

According to a report in the Guardian, the meeting could open the door for diplomatic relations between the US president and the Iranian leader - and enable a discussion on the Islamic Republic's nuclear programme and the ongoing chemical weapons crisis in Syria.

The rumoured encounter, which could take place in a corridor rather than a UN room, would mark the first time US and Iranian leaders have met since Iran’s 1979 revolution.

William Hague is also due to meet Iranian foreign secretary Mohammad Javad Zarif at the UN General Assembly next week.