"We've been saying we will observe a government decision (on Iranian oil imports), but we can't comment further as we don't disclose information on individual trades", a spokeswoman for wholesaler Showa Shell Sekiyu told AFP on Monday. "Is demand going to continue as strongly as it did?"
Add to that years of underinvestment as a result of an oil price that struggled below $50 a barrel, and some big investors believe the market is ripe for a rally.
In June, for example, OPEC agreed with Russian Federation and other oil-producing allies last month to raise output from July - with Saudi Arabia pledging a "measurable" supply boost. Iran is OPEC's third largest crude oil producer. With concerns growing that global spare capacity will be stretched if other producers such as Saudi Arabia pump more to make up for the loss, the oil market is revealing risks of a crunch.
Currently, Iran is the 3rd largest manufacturer among the Organization of the Petroleum Exporting Countries and has achieved a milestone in oil futures traded in the United Kingdom have increased to its highest with an expectation of Iranian supply loss.
The reversal in oil prices from early July highs was triggered by easing threats of the tropical storm Gordon hitting the Gulf of Mexico.
The latest threat was in July when Rouhani said Iran has always guaranteed the security of the strait but warned the United States "should not play with the lion's tale". People often focus on the supply side - what happens if Iran stops supplying - but what happens if China reduces its consumption?
"I see that as a possibility as well".
President Trump will likely move ahead this week with more duties for Beijing, putting in place another $200 billion in tariffs on Chinese goods, Bloomberg reported on Friday, citing six people familiar with the matter.
China surpassed the U.S.to become the world's largest crude oil importer in 2017, importing 8.4 million barrels per day (b/d), compared with 7.9 million b/d for the U.S., according to the U.S. Energy Information Administration. As per the trade data and Reuters, the company has set a record discount price of its crude oil for September since 2004. Russian production has now surpassed the Soviet era peak above 11 million barrels per day. According to a private survey, export orders have dropped down for the fifth straight month.