Asian imports of Iranian crude rose by 19.8 percent last year to hit a three-year high, although further increases by the OPEC nation's biggest buyers will depend on whether Tehran and world powers can settle the dispute over its nuclear programme, Reuters reported.
Imports by Iran's four biggest buyers - China, India, Japan and South Korea - averaged 1.12 million barrels per day (bpd) in 2014, government and tanker-tracking data showed, the highest since the region took more than 1.5 million bpd in 2011.
Soaring imports last year by China and India after the partial easing of economic sanctions at the end of 2013 more than offset declining shipments into Japan and South Korea.
December imports into Asia rose 22.1 pct from a year ago to 1.21 million bpd - the highest since May - due to a huge jump in India's imports for the month and higher seasonal winter demand.
Iran agreed with the United States and five other world powers in 2013 to work towards a permanent agreement on its nuclear programme in exchange for an easing of some sanctions.
Two deadlines for a final deal have slipped since then, and now the goal is to reach a political understanding by the end of March, with a view to a lasting agreement by a self-imposed June 30 deadline.
Iran called talks with France, Germany and Britain on Thursday "promising" but some analysts have cast doubts on any agreement by the new target dates.
And until a final agreement is reached, most of the Middle Eastern nation's Asian buyers are unlikely to increase their imports except China, sources said.
India has asked its refiners to slash oil buys from Iran in the next two months to keep its imports in line with the previous fiscal year's levels, sources with knowledge of the matter told Reuters last week.
The U.S. Senate Banking Committee on Thursday advanced a bill that would toughen sanctions on Iran, but a full vote on the bill is not expected until at least March 24 in the face of veto threats by President Barack Obama.
"It looks as though the West's stance is inconsistent and the talks are unlikely to be finalised," said an oil industry analyst who declined to be identified.
The United States named nine new sanctions targets in Iran at the end of December, a move that Iran's foreign ministry said "raises doubts about America's intentions and violates the good will principles" of the nuclear negotiations.
The West say Iran's nuclear activities are aimed at making a weapon. Tehran says it is making fuel only for power generation.
Under the interim agreement of November 2013, Iran is allowed to keep exports at about 1 million bpd versus a total of 2.2 million bpd before toughened sanctions were put in place in early 2012.