US President Barack Obama is struggling to convince US politicians about a possible deal with Iran on its nuclear programme. Talks resume today in Geneva about the nuclear ambitions of Tehran.
The British Prime Minister David Cameron has made a ground breaking phone call to Iranian President Hassan Rouhani ahead of the talks, which is the first call of its kind in more than a decade.
Dr. Rouhani gave details of the phone call on his Twitter feed, saying they discussed "ways to create a positive atmosphere to address concerns on both sides on the nuclear issue".
The pair also discussed finding a political solution to the Syrian crisis and improving bilateral ties.
US President Obama says it is worth taking a risk on a possible deal.
Iranian Foreign Minister Mohammad Javad Zarif said on the eve of the meeting there was "every possibility" of a successful conclusion provided there was good faith and the political will among all those involved to resolve problems.
The US, Russia, China, France, Britain and Germany came close to winning concessions from Iran on the scope of its nuclear programme in return for some sanctions relief during three days of high-level talks in Geneva earlier this month.
The US Secretary of State John Kerry said Iran had been unable to accept a deal "at that particular moment", but Tehran blamed divisions between Western powers.
Top policymakers from the sextet have since said an interim accord on confidence-building steps to start defusing a decade of suspicion and hostility between the West and Iran could finally be within reach. But diplomats have warned that differences remain and could still prevent a deal.
Iran's nuclear reactor being built at Arak figured highly in the recent failed talks in Switzerland.
A United Nations nuclear watchdog report last week showed Iran had stopped expanding its enrichment of uranium and had not added major new components at Arak since August, when moderate Dr. Rouhani replaced hardliner Mahmoud Ahmadinejad as President.
Image: UN Photo/Jennifer S Altman
