The Islamic Republic exported 1.1 million barrels per day (bpd) of crude in that seven-day period, Refinitiv Eikon data showed.
"Of course it could find alternative supplies, from other parts of the Middle East or from the United States itself", said Leszczynski. The bulk of spare capacity is held by Saudi Arabia. Last applied from 2012 to 2015, the sanctions are in retaliation for Iran's supposed nuclear proliferation program.
President Donald Trump has pulled the USA out of a historic 2015 accord with energy-rich Iran signed to curb the Islamic republic's nuclear programme in return for ending sanctions.
Last week, India reduced gasoline and diesel prices to give relief to consumers against rising global crude prices caused by uncertainty over USA sanctions on Iran and OPEC's decision to raise output. A second round, forthcoming on November 4, will be targeting Iran's oil sales and its Central Bank.More news: Jose Mourinho given private support from Manchester United
Alongside potential waivers on Iranian sanctions, oil supply is seemingly back on the rise with Libya recently boosting oil production to 1.25mbpd (200kbpd more than the September average).
Oil also dropped as investors focused on rising output from other producers, such as top exporter Saudi Arabia, to compensate for lower Iranian supplies.
Ralph Leszczynski, Banchero Costa's head of research in Singapore, tells TradeWinds: " The US sanctions on Iranian oil imports are strictly unilateral, as they have been actively resisted by other buyers of Iranian oil. "We will be guided by our national interest", he added.
Iran has warned that if it were not able to export its crude oil through the Strait of Hormuz, no other country would be able to do so, threatening to block the strategic strait.More news: Trump does victory lap after bitter Supreme Court battle
He said: "We expect the global leadership to acknowledge India's need for Iran's oil".
He emphasized that any arrangement for the sale of oil in the region "should be inclusive" and added, "If you exclude one country [and] make sure that one country's oil sale comes to zero, as President Trump wants, that would create problems for the whole region".
Oil prices rose on Tuesday as more evidence emerged that crude exports from Iran, OPEC's third-largest producer, are declining before the imposition of new US sanctions and as a hurricane moved across the Gulf of Mexico.
The official, who spoke on the condition of anonymity, said the administration was "in the midst of an internal process" of considering exceptions called SRE waivers, or significant reduction exemptions.More news: Microsoft announces its take on game streaming: Project xCloud