The US has asked the Japanese government to withdraw from Iran's Azadegan oil field project in which Japanese oil developer Inpex Corp has a stake, a Japanese newspaper reported on Wednesday.

The Yomiuri newspaper quoted a Japanese government source as saying Washington has suggested Inpex could be mentioned in a new list of Iran-related firms to be targeted for US sanctions and urged Tokyo to cooperate by dropping the investment.

Japan's government is the biggest shareholder of Inpex, with an 18.9 per cent stake after a recent multi-billion dollar share sale.

Earlier this month, Japan imposed additional sanctions on Iran, following the US and European Union in pressuring Tehran despite Tokyo's reliance on oil imports from the country.

At that time, Japan's then trade minister, Masayuki Naoshima, said he did not expect any major change in Inpex's investment, currently Japan's sole energy-related stake in Iran.

When tension was growing in 2006 between the US and Iran over the country's uranium processing and nuclear power development, Inpex cut its stake in the Azadegan oil field project to 10 per cent from 75 per cent. – Reuters