Warmer relations for the US and Iran?
24 September 2013 Last updated at 23:27 BST
Recent moves by Iran should offer the basis for a "meaningful agreement" on its nuclear programme, US President Barack Obama has told the UN General Assembly.
Meanwhile, in his speech later in the day, Iranian President Hassan Rouhani insisted that his country posed "absolutely no threat to the world or region".
Since his election, President Rouhani has shown signs of a great willingness to work with the West, but hopes of a symbolic meeting between both presidents at the UN were dashed.
Middle East editor Jeremy Bowen reports from New York.