Iran can export around 1 million bpd under the terms of a November arrangement that brought some relief from economic sanctions in exchange for a commitment to curb nuclear research activity. In the wake of the agreement, Iran said it was in serious negotiations with the Russian government to swap oil for goods.
Both sides already cooperate in the energy sector, with Russia supplying fuel for Iran's nuclear reactor in Bushehr.
A source inside in the Russian government told Russian business daily newspaper Kommersant the U.S. government "attempted to torpedo the [oil] deal by threatening both Russian and Iranian companies with sanctions."
When the deal surfaced early this year, U.S. Rep. Ed Royce, R-Calif., chairman of the House Committee on Foreign Affairs, said it was "very troubling" that Iran may be able to export an additional 500,000 barrels of oil under the terms of the agreement.
Marie Harf, a spokesperson for the U.S. State Department, said at the time there were "no indications" that such a deal existed.
Russian and Iranian officials are scheduled to meet in Tehran in September to discuss their economic partnership.