"We are not getting any oil from Iran now," said the Turkey's official, who spoke on condition of anonymity. "We were one of the eight countries getting an exception from those sanctions, and now we are ready to abide by them," he said.

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.

An Iranian official said the exports of natural gas to Iraq are growing steadily and are expected to hit 40 million cubic meters a day in summer.

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.

Russian-built Bushehr 1 - the first nuclear power unit in the Middle East - was connected to the national grid on 3 September 2011. Bushehr units 2 and 3 are to be completed in 2024 and 2026, respectively.

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.”

China's crude oil imports from Iran, the March volume rose 6.2% from February on a barrels-per-day basis, despite dropping by a quarter from the same month of last year.