Russian officials say it is too soon to say when an oil-for-goods arrangement with Iran will start, despite earlier reports that Moscow had already begun delivering on the deal.

The deal could help Moscow, which faces Western sanctions over the Ukraine crisis, by strengthening its foothold in Iran. But there is no agreement yet between Tehran and world powers on Iran's nuclear program that would relax sanctions on the Islamic republic.

Russia's food-safety regulator said on June 8 that grain sales to Iran had begun, RIA news agency reported, though the regulator later backed off that claim.

Iran's Fars news agency, moreover, quoted Iran's oil minister on June 6 as saying Russia would begin oil imports from Tehran this week.

But the Russian Energy Ministry later said it was too early to talk about starting the deal.

Russia hopes to act as an intermediary selling oil for Iran under the swap arrangement, which Iran's ambassador to Moscow estimated was worth $70 billion.

Based on reporting by Reuters and TASS