Iran's gasoline imports for August look set to be around half those of the previous month and have plunged by almost 90 per cent from a year ago, according to Reuters calculations based on trade sources.

A new round of US and EU sanctions has very effectively choked off many potential suppliers to Iran, whose limited refining capacity means it has had to import up to 40 per cent of its gasoline needs, even though it is the fifth biggest oil exporter.

Figures so far showed Iran would in August be importing only two cargoes of gasoline, or around 18,000 barrels per day (bpd), assuming standard cargo sizes of around 280,000 barrels.

That marks a deep drop from the same time a year ago when Iran bought 15 cargoes of gasoline, or nearly 135,500 bpd of the motor fuel from international markets.

"A year ago the West was still just talking about the sanctions ... nothing was getting done, that isn't the case today. We have the world breathing down Iran's neck," a Singapore-based trader said.

Many potential suppliers have stepped away, although analysts say Russia and China have reasons for seeking to maintain a relationship with Iran that faces punitive Western measures over its nuclear programme.

Iran has said its nuclear plans are solely aimed at producing energy and not at developing a nuclear bomb.

Both permanent members of the UN Security Council, Russia and China signed up to the latest round of UN sanctions on Iran, but they refused to support measures that targeted its oil and gas sector.

Subsequent EU and US sanctions by contrast have made it much more difficult to carry on fuel trade with Iran, analysts and traders have said.

"This a quite a tough year for Iran. They didn't manage to get the stocks they needed before Ramadan and this month we hear that only 1-2 cargoes made it," said one Gulf-based trader.

Ramadan -- when Middle Eastern demand rises as people travel on holiday -- started on the second week of August, and last month only three to four cargoes were shipped into Iran, according to documents seen by Reuters.

Iran's Opec governor Mohamed Ali Khatibi told Reuters this week any drop in import levels was merely a reflection of lower demand.

Earlier this year, Iran reduced the monthly allowance of fully subsidised gasoline and officials have said queues to buy fuel are the result of consumers buying little and often, rather than because of an overall shortage of supply. – Reuters