World powers resume crisis talks with Iran on Monday amid hope that a crippling oil embargo and pressure from host Russia will finally force the Islamic Republic to scale back its nuclear drive.

The two-day meeting follows a bruising May session in Baghdad during which Iran nearly walked out of negotiations aimed ultimately at keeping it from joining the exclusive club of nations with an atomic bomb.

Host Russia however is keen to flex its diplomatic muscle and make Iran an example of how Moscow's influence over Soviet-era partners could be used to avoid foreign military intervention in the 16-month crisis in Syria.

"There are reasons to believe that the next step will be taken in Moscow," Russia's Deputy Foreign Sergei Ryabkov said.

Failure in Moscow could leave the process in tatters and raise the threat of air raids from arch-foe Israel -- a fateful scenario in which broader conflict would lead to a spike in oil prices that could tip over the world's teetering economy.
But Western officials have also made clear that Iran's current position would leave them no choice but to go ahead with the oil sanctions while considering new ones in the months to come.

They add that the two sides still remain far apart despite the mounting pressure.

The offer outlined by the powers last month and under discussion in Moscow would see Iran stop enriching uranium to 20 percent -- seen as being just steps away from weapons-grade -- and ship out its existing stock while shuttering its Fordo bunker.

Iran, world powers set for showdown in Moscow - Yahoo! News