Iranian officials said the issue is likely to be discussed during talks between Iranian Foreign Minister Mohammad Javad Zarif and External Affairs Minister Salman Khurshid here tomorrow.
They said Iran may offer India the option of making the payments through central banks of Germany and Switzerland following easing of the sanctions.
"The negotiations are on the issue," said an official declining to elaborate further.
Asked about quantum of outstanding dues, officials refused to give the details but said it was in excess of USD one billion and Iran will press for early payment of the dues.
Due to sanctions on Iran, India had cut imports from the Persian Gulf nation from 21 million tonnes to about 18 million tonnes in 2011-12 and to 13.1 million tonnes in 2012-13.
The US and five other world powers struck an accord with Iran in November last year, agreeing to ease part of an economic stranglehold in exchange for steps to cap Tehran's nuclear programme and ensure the Islamist government doesn't rush to develop atomic weapons.
India imported 6.74 million tonnes of crude oil from Iran during the first nine months of the current fiscal.
The imports during April-December are 61 per cent of the target of buying 11 million tonnes of oil from the Persian Gulf nation in the current fiscal.
Iran, which was India's second biggest supplier of crude oil after Saudi Arabia in 2010-11, slipped four places to become its seventh-largest crude oil supplier in 2012-13.
