The US President Barack Obama has said any deal on the Iranian nuclear could see relief in sanctions against them.
It comes as the US Secretary of State John Kerry is expected to join the talks in Geneva later.
The last minute decision by Mr. Kerry - who is also making a brief stop in Israel - could suggest a deal is imminent.
Iran has been negotiating with the West to curb some of its nuclear activities in exchange for limited relief from sanctions.
Speaking to NBC News yesterday, US President Obama said sanctions against Iran may see a 'modest relief' on foot of any such deal.
Meanwhile the Israeli Prime Minister Benjamin Netanyahu has dismissed an agreement expected to made between world powers and Iran as a "bad deal".
"I understand the Iranians are walking around very satisfied in Geneva as well they should because they got everything and paid nothing" he said.
"They wanted relief of sanctions after years of gruelling sanctions, they got that. They paid nothing because they are not reducing in any way their nuclear enrichment capability. So Iran got the deal of the century and the international community got a bad deal".
"This is a very bad deal and Israel utterly rejects it. Israel is not obliged by this agreement and Israel will do everything it needs to do to defend itself and defend the security of its people" he added.
A senior US State Department official travelling with US Secretary of State Kerry said he was going to Geneva "to help narrow differences in negotiations".
Six world powers - the United States, Russia, China, Britain, France and Germany - are working with Iran on the deal to cap some of its atomic programmes in exchange for limited relief from economic sanctions.
The Russian Foreign Minister Sergei Lavrov said a "road map" to end the differences over the programme at the talks.
White House spokesperson Jay Carney spoke to reporters at his regular press conference yesterday.
Main Image: NBC News