Beijing, however, agreed not to increase purchases of Iranian crude, said the officials who spoke on condition of anonymity.
The U.S. has told all countries, including India to stop their oil imports from Iran by November 4 or face sanctions for carrying out any transaction with Tehran as there would be "zero" waivers to any country.
With tensions high ahead of the return of U.S. sanctions on Tuesday, the government of President Hassan Rouhani also faces opposition from conservatives and religious leaders, who have long disliked his outreach to the West and accuse him of governing only for the rich.
Iranian protesters have attacked a religious school in Karaj province near Tehran, the Fars news agency reported on Saturday, as sporadic protests simmered ahead of the reimposition of U.S. sanctions. The activity extended to the Strait of Hormuz, a strategic waterway for oil shipments the Revolutionary Guards have threatened to block.
USA officials have softened their stance after initially saying they would press allies in Europe, Asia and the Middle East to adhere to the sanctions and reduce their imports to zero.
They said they remained committed to the 2015 accord and to building up economic relations with Iran, including "the continuation of Iran's export of oil and gas" and other energy products.
Iranian protesters have attacked a religious school in Karaj province near Tehran, a conservative Iranian news agency has said, as sporadic protests simmered ahead of the reimposition of USA sanctions.
Day in Tiger's group at WGC at Firestone
On his WGC debut earlier this year in Mexico the Indian led through 54 holes before ending the week T9. Woods is playing the opening rounds of this tournament with a two-time victor this season, Jason Day .
"At 9pm [15:30 GMT on Friday] they attacked the school and tried to break the doors down and burn things", the Fars News Agency quoted the head of the school in the town of Ishtehad, Hojatoleslam Hindiani, as saying.
The U.S. has been pushing its allies to halt their import of Iranian oil ahead of the November deadline.
India, the second purchaser of Iranian crude, also increased its imports from Iran last month.
Iran wants guarantees from Europe to maintain banking cooperation and investments in Iran's oil fields as well as continuation of cooperation between Iranian and European small and medium-sized enterprises, Qasemi noted.
The official confirmed that during July delegations would be dispatched to Beijing and Delhi to press home the case, having already visited the capitals of other major Iranian oil importers.
Tamar Essner, an analyst at Nasdaq Inc., said there are "no signs whatsoever that this trade war is going to clear up anytime soon", and that has "caused investors to continue to trim net length, take profits, and de-risk that position with the sense that oil's upside is limited unless there's material reduction in Iranian barrels".