Iran has begun talks with Japanese companies under a U.S. sanctions waiver allowing it to resume oil sales, though prospective buyers are seeking a longer waiver and reassurances about ship safety, three Iranian and Western sources said.

The waiver, part of 60-day peace talks between Tehran and Washington, was issued on June 22 and expires August 21.

Three Japanese buyers were looking at possible crude oil purchases from Iran, their first since 2019, said two Iranian sources, who declined to be identified due to the sensitivity of the issue.

Japanese and Iranian officials were in initial talks about possible oil sales, a Western industry source familiar with the matter said separately.

An official at Japan's Ministry of Economy, Trade and Industry (METI), which oversees fuel supply infrastructure, said he was unaware of any such matter.

Japan's foreign ministry and the U.S. Treasury did not immediately respond to Reuters requests for comment.

Japan, South Korea, India and European countries stopped buying Iranian oil when U.S. sanctions tightened following U.S. President Donald Trump's withdrawal from Iran's nuclear pact in 2018.

China has been Iran's main buyer in recent years.

Hormuz risks

Any Japanese purchases would be a matter for private companies, a separate METI official told Reuters in June, but said it was unclear whether such deals would proceed given shipping times and existing contracts.

The safety of any tanker voyage would also have to be ensured, the official added.

A senior Iranian official said any deal would require the U.S. to extend the current waiver given the shipping time between Japan and Iran.

The official added that cargoes would be loaded at Iran's Kharg Island and use Japanese-operated tankers.

A senior Iranian oil ministry official told Reuters that Iran's national oil company NIOC had approached traditional customers including Japan and told them that if a peace deal was concluded and sanctions were lifted, Iran would like them to resume their purchasing.

Iran's oil ministry did not respond to a request for comment.

The Strait of Hormuz ship passage is still far from safe and how it will operate once a lasting peace deal between Tehran and Washington is finalised is not yet known.

A container ship was attacked in the Strait of Hormuz last week by Iranian forces and Iran's elite Revolutionary Guards have said all transits through the strait need to be cleared with them first.

The U.N.'s shipping agency estimates that there are 80 floating mines around the central part of the waterway.

Securing insurance would be the biggest challenge, a senior official with a major Japanese oil refiner said.

The current temporary U.S. sanctions waiver was unlikely to draw orders from well-stocked Asian refiners, leaving independent Chinese refineries as the main buyer, trade sources and analysts have said.