Russia sees a range of options that would allow OPEC+ to continue output cooperation until year-end, from easing the limits to ending the extreme throttling-back that has seen some countries exceed original cutback targets.

OPEC+ would take action to offset losses of Iranian supply if market fundamentals justified it. However, no policy changes will be made until the next full OPEC+ meeting in Vienna, in June.

Iran has sent abroad between 250,000 bpd and 500,000 bpd of oil so far in May, according to two industry sources who track the flows. Data from Refinitiv Eikon put crude shipments at about 250,000 bpd and exports of crude and condensate, a light oil, at about 400,000 bpd.

The region needs more peace and stability to ensure the flow of oil supplies, Mohammad Sanusi Barkindo, Secretary-General of the Organisation of the Petroleum Exporting Countries, OPEC, has said, noting that, "Any tension that occurs in the region affects the whole world."

The sanctions have already more than halved Iranian oil exports to 1 million bpd or less, from a peak of 2.8 million bpd last year. Exports could drop to as low as 500,000 bpd from May, an Iranian official told Reuters this month.

OPEC's collective crude oil production in April held relatively steady from March, rising just 30,000 b/d to 30.26 million b/d,

Russia is meeting its obligations under the OPEC/non-OPEC crude production agreement, and participants remain committed to the arrangement, despite ongoing uncertainty over world energy market developments.

OPEC is due to meet in June, where the Iran question will no doubt be raised. But oil and gas leaders are taking a cautious approach, with Kuwait's oil minister Khaled Al Fadhel noting that a decision would be taken only after a review of oil prices.

Asked whether Iran’s oil could be removed from the market, Mr. Barkindo said: “No repetition is needed. Eliminating Iran from the oil market is impossible.”

The International Energy Agency is monitoring developments in global oil markets, and notes that markets are now adequately supplied, and that global spare production capacity remains at comfortable levels.