South Korea imported 232,723 tons (1.71 million barrels or 55,161 bpd) of Iranian crude, including condensate, in August, according to preliminary data released by the Korea Customs Service on Monday.
The data is based on customs clearance and there can be a time discrepancy between clearance and actual arrival of the goods, according to customs officials, Platts reported.
Final oil trade data for August will be released later this month by state-run Korea National Oil Corp.
For the first eight months this year, Iranian crude oil imports fell 42.3 percent year on year to 57.91 million barrels, from 100.44 million barrels in same period last year, according to the customs data.
In 2017, Iranian crude oil imports increased 32.1 percent to 147.87 million barrels. The country's monthly imports of Iranian crude had increased since January 2016 when the US and EU lifted sanctions on Iran.
The US has pressed Iran's oil customers, including South Korea, to completely eliminate imports by November 4. South Korea's crude oil imports from its biggest supplier Saudi Arabia also fell 4.8 percent year on year to 3.89 million tons, or 28.51 million barrels, in August, from 29.95 million barrels a year earlier.
In total, South Korea imported 12.62 million tons (92.5 million barrels or 2.98 mbd) of crude oil in August, down 8.8 percent from 101.45 million barrels a year earlier. But the August imports were also down 4.3 percent from 96.67 million barrels in July.
For January-August, the country's crude oil imports rose 1.2 percent year on year to 746.62 million barrels, compared with 737.72 million barrels in the year-ago period.
In 2017, the country imported a total 1.118 billion barrels of crude oil, up 3.7 percent from 1.078 billion barrels in 2016.