The Trump administration slapped sanctions on Iran oil exports in May after ditching the Iran nuclear deal, and the sanctions on Iran's energy sector are set to kick in on November 4.
India and other key importing countries have been engaged for months with the USA for a waiver.
Iranian President Hassan Rouhani has warned Iranians they face hard times when new USA sanctions take effect on Sunday but said the government would do its best to alleviate them.
Washington earlier said that their expectation was that importers from Iran would be reduced to zero.
Up until this week, the move to limit Iranian oil exports was seen as a bullish argument for crude oil prices.
According to details leaked from waivers talks, India has agreed to reduce Iranian oil imports by about 40 percent below planned levels to about 1.25 million metric tons per month, or about 290,000 barrels per day.
The sanctions will penalise countries that do not end importing Iranian oil and foreign companies that do business with blacklisted Iranian firms.More news: Special counsel Mueller's team asks Federal Bureau of Investigation to probe 'false claims' against him
"We have advised SWIFT that it must disconnect any Iranian financial institutions that we designate as soon as technologically feasible to avoid sanctions exposure".
No final decision has been made and an announcement is unlikely before US sanctions on Iran are reimposed November 5, the officials said, asking not to be identified because the information is confidential. Iran, however, has said that it has been using the program for internal purposes of civilian development like producing electricity and medical use.
"Trump is showing his disdain for the Iranian people through these sanctions", Trita Parsi, founder of the National Iranian American Council, a nonprofit organization in Washington that advocated in support of the nuclear deal.
That's up 390,000 bpd from September and the highest by OPEC since December 2016, just before the group started to voluntarily withhold supply in January 2017 in order to prop up prices.
That's symbolically important to the Trump administration because President Barack Obama's administration took three years to remove 1.2 million barrels from the market - and that was while acting in concert with the European Union and other nations before the global effort yielded the 2015 deal. In addition, U.S. nationals and its entities were not allowed to carry on business with Iran. Other countries, including Iraq and Afghanistan, depend on some imports from Iran. Rouhani urged Parliament to approve four new ministers and help his government "resist" and "fight" the U.S.as it reinstates sanctions against the Islamic Republic. I am asking for WORLD PEACE, nothing less!
The U.S. has reportedly broadly agreed to grant India a waiver from the sanctions, after Iran's second-largest oil customer had agreed to reduce Iranian imports by a third in 2018-2019, India's The Economic Times reported on Thursday, citing sources familiar with the issue.