According to Reuters, South Korean imports of Iranian crude nearly doubled in May from a year ago, but due to international sanctions, its shipments from the OPEC country in the first five months of 2015 fell 2 percent year-on-year.
Seoul imported 541,510 tons of crude from Iran last month, compared with 284,327 tons a year ago, preliminary customs data from the world's fifth-largest crude importer showed on Monday.
South Korea and other Asian buyers can import crude from Tehran at sanctions-reduced rates reached in 2013.
Iran and the 5+1 group of countries - the US, Britain, France, Russia, and China plus Germany – have been working on the text of a final deal over Tehran’s nuclear program since they reached the mutual understanding on its parameters on April 2.