Nearly all of Iran's main customers purchased fewer Iranian barrels in August than they did in April, the month before Trump said sanctions were being reimposed.
Then there's the fact that India is heading into an election year.
However, prices were able to rebound into the close on Friday after a report said Secretary of State Michael Pompeo was going to give a press conference on new sanctions on Iran.
India, Iran's No.2 oil client behind top buyer China, does not recognize the reimposed United States sanctions, but winning a waiver from the restrictions is a must for New Delhi to protect its wider exposure to the U.S. financial system.
Iran's oil exports started to drop noticeably in August, and many analysts now expect the sanctions to remove more than 1 million bpd of Iranian oil from the market.
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Leading traders such as Vitol CEO Ian Taylor and Royal Dutch Shell's former head of crude trading Mike Mueller have been among those to express concern about the long-term decline in North Sea production and its impact on the liquidity of the market that sets the price of dated Brent.
Refiners in India, traditionally major buyers of Iranian crude, will cut their monthly loadings from Iran for September and October by almost half from earlier this year. Here are the production numbers of the OPEC countries in the past two months.
Market participants will be taking further price action cues from the latest Baker Hughes rig count data - an early indicator of future U.S. crude production - that is due for release later Friday.
International Olympic Committee would also lift 1 million barrel for its subsidiary Chennai Petroleum Corp in October, they said. There are now eight tankers holding 14 million barrels of Iranian crude or condensate, a form of light crude extracted from gas fields, anchored in the Persian Gulf.
Hindustan Petroleum, Reliance Industries and HPCL Mittal Energy (HMEL) have no plans to buy from Iran in September and October, they said.
Crude futures ended the week up more than 1.6 percent.
IOC, Nayara and MRPL did not respond to Reuters' emails seeking comments.