US Secretary of State Mike Pompeo and Defense Secretary Jim Mattis are on an official visit to India with a top agenda priority of pressuring New Delhi to stop buying Iran’s oil.

A senior US State Department official, who was not named in reports, said on Thursday that American and Indian officials were engaged in “very detailed conversations” to persuade India to stop oil imports from the Islamic Republic.

“We’re asking all of our partners, not just India, to reduce to zero oil imports from Iran, and so I’m confident that will be part of our conversation with India,” the official said as Pompeo and Mattis met with their counterparts in the Indian capital.

“There are very detailed conversations taking place between the US and India on just the technical issues related to going to zero and those conversations will continue,” the official added.

This handout photo, from India’s Ministry of External Affairs, taken on September 6, 2018, shows US Secretary of Defense Jim Mattis (top-4th-R) and US Secretary of State Mike Pompeo (top-3rd-R) meeting with India’s Foreign Minister Sushma Swaraj (4th-L) alongside other delegates in New Delhi, India. (Via AFP)

Iran reached a deal with originally six world powers in 2015, agreeing to curb its nuclear program in return for mainly the lifting of restrictions on its oil sales.

The administration of US President Donald Trump — which took office some two years after that deal had been struck — unilaterally withdrew the US from the agreement on May 8, over the objections of Europe as well as Russia and China.

Iran has remained in the deal but has stressed that for it to continue to stay in the agreement, the remaining parties have to offset any adverse effects of the US withdrawal and guarantee that Iran will continue to collect the economic benefits that it is contractually entitled to.

Europe, Russia, and China are now working with Iran to map out a potential course without the US.

The American withdrawal has entailed not only the re-imposition of unilateral US sanctions on Iran but also the so-called secondary sanctions on third countries that would continue to do business with the Islamic Republic.

A first round of American sanctions — targeting Iranian access to the US dollar, metals trading, coal, industrial software, and auto sector — took effect on August 7. A second round, forthcoming on November 4, will be targeting Iran’s oil sales and its Central Bank.

The Trump White House has said that it seeks to bring Iran’s oil sales supposedly down to “zero.” It has since been pressuring Iran’s crude clients to halt their purchases from the Islamic Republic.

India is the world’s third-biggest oil importer and Iran’s second after China.

New Delhi has formerly said it will not comply with unilateral sanctions on Tehran. Yet, India’s oil imports from Iran plunged by a third in August as state refiners waited for government permission to buy oil using Iranian tankers and cover.

This week, New Delhi allowed its state refiners to use Iranian tankers and insurance cover after Western and Indian shippers started winding down their Iran operations ahead of the sanctions due in November.