NEW DELHI- Indian refiners would resume imports of Iranian oil if the United States eases sanctions against Tehran, the chairman of state-run Hindustan Petroleum Corp said on Thursday.

U.S. President Joe Biden's administration is seeking a diplomatic solution to the nuclear dispute with Iran, which could see sanctions eased.

India, which was Iran's top oil client after China, had stopped oil imports from the OPEC nation in mid-2019 under pressure from the stringent sanctions imposed by former U.S. President Donald Trump.

"Iranian crude had been in the (import) basket of Indian refineries ... we will be happy to take that crude as and when the situation warrants and the crude is available," M.K. Surana told a news conference.

Washington has been at loggerheads with Tehran for decades and relations between the two countries worsened under Trump, who withdrew from the 2015 nuclear deal between Iran and six world powers, and imposed more sanctions on Tehran.

On Monday, Iranian Foreign Minister Mohammad Javad Zarif for the first time hinted that Washington and Tehran should take synchronized steps to return to the Iran nuclear deal abandoned by Trump. 

Surana said Iran was previously offering favourable terms for payment and freight discounts among others which made its oil "preferential" compared to other grades.

After stopping purchases from Iran, Indian refiners have diversified their crude imports.

"There are alternatives in the picture after that (sanctions). Now US crude is coming to India," he said.

Oil minister Dharmendra Pradhan last year said India, the world's third biggest oil importer and consumer, wants to diversify its oil imports, including the resumption of supplies from Iran and Venezuela, under Biden's rule.

Surana said refiners evaluate alternative crudes available in the market and the value they generate to maximise revenue. "But yes, there is possibility. If the (Iranian) crude is available people will definitely look at those options," he added.

(Reporting by Nidhi Verma; editing by David Evans) ((nidhi.verma@thomsonreuters.com; +91 11 49548031; Reuters Messaging: nidhi.verma.thomsonreuters.com@reuters.net))