France, Sept. 23 -- Iran and Europe's leading powers are racing on the sidelines of the the UN General Assembly to strike a deal on Tehran's nuclear programme before a 27 September deadline triggers the return of sanctions.

As the UN General Assembly gets into full swing in New York, Iran and Europe's so-called E3 - Britain, France and Germany - are engaged in frantic back-room diplomacy aimed at stopping the reimposition of UN sanctions on Tehran over uranium enrichment.

Foreign ministers from the four sides, joined by the EU's new foreign policy chief Kaja Kallas, are meeting on Tuesday in what is being billed as a final attempt to salvage some space for negotiation.

It follows weeks of rising tension over Iran's nuclear programme, w...