Iran, which on Monday said it planned to halt oil sales to several more European Union states in addition to Britain and France, sends only around a fifth of its exports to the EU, with Asian countries taking the lion's share, according to US and international oil agencies.
The Energy Information Administration (EIA) in Washington says that in 2010 four Asian states took around two-thirds of all the crude oil exported by the Islamic Republic, with China buying 20 percent, Japan 17 percent, India 16 percent and South Korea 9 percent.
A separate body, the International Energy Agency (IEA), reports that Iran supplies between 6 and 10 percent oil consumption in the four Asian nations.
China's imports of 550,000 barrels per day (bpd) covered 6 percent of its needs in the first 10 months of 2011, while India's purchases of 310,000 bpd accounted for 9 percent of its needs.
Japan meanwhile took 327,000 bpd from Iran, or 7 percent of its needs, and South Korea bought 228,000 bpd (10 percent) from the Islamic Republic.
The IEA reports that just over 20 percent of Iran's crude exports in the first 10 months of 2011 went to European Union states, predominantly in southern Europe.
The EU's share of Iranian sales came to around 600,000 bpd over the period, out of total Iranian exports of 2.5 million bpd, the agency said.
It said the main takers of Iranian crude in the EU were Italy, which imported 185,000 bpd over the period, Spain (161,000 bpd), and Greece (103,000 bpd).
The three countries accounted for 75 percent of all Iran's exports to EU states; Iranian oil provided 13 percent of Italy's oil consumption, 12 percent of Spain's and 30 percent of Greece's, according to IEA figures.
Among the other 24 EU nations, none is heavily dependent on Iranian oil imports, the agency said.
France took 58,000 bpd of Iranian crude, or 3 percent of its needs, over the period, Belgium 36,000 bpd (5 percent of its needs), the Netherlands 19,000 bpd (2 percent), Germany 15,000 bpd (1 percent), Britain 11,000 bpd (1 percent), the Czech Republic 5,000 bpd (3 percent) and Poland 3,000 bpd (1 percent).
Two non-EU states that are more heavily dependent on Iranian oil are Turkey, which took 196,000 bpd or 29 percent of its needs over the period, and South Africa, which imported 80,000 bpd or 14 percent of its demand.
Iran's known reserves of crude oil are the fourth largest on the planet, after Saudi Arabia, Venezuela and Canada.
The country is currently the second-biggest exporter of crude in the Organisation of Petroleum Exporting Countries, after Saudi Arabia, and the world's third biggest exporter after Saudi Arabia and Russia.