Six major world powers and Iran are due to hold a second round of talks on Tehran's nuclear ambitions.  The two days of meetings in Geneva follow last month’s discussion hailed by participants as “substantive and forward-looking.”

Those earlier talks concluded with international negotiators considering an Iranian proposal.  This time, an anonymous US official says America is hoping that Iran will agree to “an initial understanding that stops Iran's nuclear program from moving forward and rolls it back for the first time in decades.” 

Overall, International negotiators want Tehran to take specific steps to prevent it from ever being able to make nuclear weapons.  In return, they promise to lift some economic sanctions.

The negotiations bring Tehran together with the five permanent members of the UN Security council (The US, Britain, China, France, Russia), plus Germany – a grouping known as “P5+1”.

The West suspects Iran of seeking to build nuclear weapons. Tehran says its nuclear program is only for generating energy and for use in medical research.