The country, the 3rd-biggest producer of crude within the Organisation of the Petroleum Exporting Countries, exported about 2.6 million barrels per day (bpd) in April.
The back and forth Friday came as thousands of Iranians took to the streets in cities across the country to protest President Trump's decision this week to re-impose sanctions, arguing the 2015 nuclear deal that lifted sanctions wasn't tough enough on Iran.
Countries having financial dealings with Iran are expected to be hit by the comprehensive sanctions regime announced by the Trump administration after withdrawal from the nuclear deal.
"Given the back and forth between China and the U.S. on trade, Chinese compliance is probably a nonstarter", said Michael Tran, global energy strategist at RBC Capital Markets.
"We feel that the extraterritoriality of their sanction measures are unacceptable", he told the French daily Le Parisien.
"The Prime Minister raised the potential impact of U.S. sanctions on those firms which are now conducting business in Iran".
Major companies that could take a hit because of U.S. sanctions on Iran are France-based Total, Airbus, and Accor, Germ-any-based Volkswagen, Spain's Melia and US-based Boeing and GE.
While Iranian officials, including the parliament speaker, say they hope Europe will work with them to preserve the deal, President Hassan Rouhani warned Iran could ramp up uranium enrichment in the coming weeks and that there is only a short window to negotiate with the accord's remaining signatories. In their many conversations with Trump about Iran this year, the Europeans asked him to avoid damaging their own investments there, even if he decided that the United States was out of the deal, the Post reported.
Tourism in Iran had also benefited from the nuclear deal, with visitor numbers increasing from 3.8 million visitors in 2012 to over 5 million in 2015, and this could also be affected by renewed sanctions.
The Indian oil ministry has not commented on the US pullout, but the foreign ministry on Wednesday called for diplomacy to resolve the dispute over the nuclear deal with Iran.
They would have to wind up investments by November or face United States sanctions.