UPDATE 1-S.Korea crude imports from Iran unexpectedly surged in July
* July crude imports from Iran up 38 pct y/y, up 44 pct m/m
* First y/y rise since Dec of 2012
* June-July Iran oil imports 165,933 bpd vs 148,016 bpd Dec-May
* Seoul targets 15 pct cut in June-Nov imports from previous 6 mths
(Recasts; adds comment, detail)
SEOUL, Aug 15 (Reuters) - South Korea's imports of crude from Iran unexpectedly surged from a year ago in July, making it more difficult for Seoul to meet a pledge to cut oil shipments from the sanctions-hit country in the next few months.
South Korea along with China, India and other Iranian oil buyers agreed in June to reduce purchases of oil from Iran to extend a six-month waiver on U.S. sanctions targeting flows of oil money to Iran's nuclear programme.
The Northeast Asian country imported 815,447 tonnes of crude from Iran last month, up 38 percent from a year ago in the first rise this year, preliminary data from the Korea Customs Service showed on Thursday.
The imports marked a 44-percent climb from a month ago and, according to a Reuters calculations, were equivalent to 5.98 million barrels.
That means Seoul imported 165,933 barrels per day (bpd) in June-July, up 12 percent compared to the previous six months, the calculations showed. It needs to import less than 126,000 bpd in June-November to meet its pledge to Washington.
"Imports can vary month on month, as long as imports in the six months are down by 15 percent compared with the previous six months," said a source with direct knowledge of the matter. He added that relatively low prices may have boosted imports in July compared with other months.
Iranian oil importers have been reducing their imports to keep getting six-month waivers on U.S. sanctions aimed at cutting Iran's flow of oil dollars and forcing it to negotiate over curbing its disputed nuclear programme.
South Korea promised to slash its Iranian oil imports by 15 percent from the daily rate seen from December 2012 to May 2013, two sources told Reuters in June.
It imported oil from Iran at 148,016 bpd for December to May, meeting its earlier declared target of cutting imports by 20 percent from the same period a year ago to win its third waiver on U.S. sanctions. Imports varied from month to month, however, with a hike in December shipments, for example.
South Korean markets were closed on Thursday for a public holiday.
U.S. lawmakers now want to further toughen the measures that have cost Iran billions of dollars a month in lost revenue, while Iranian President Hassan Rouhani, who took office in early August, has promised moderation in Iran's domestic and foreign policies and more transparency in its nuclear programme.
South Korea, the world's fifth-largest crude buyer, imported a total of 11.16 million tonnes of crude last month, against 10.74 million tonnes in the same month a year ago.
Final data for South Korea's crude imports for July that will be published later this month by state-run Korea National Oil Corp (KNOC) is considered the industry standard.
(Reporting by Meeyoung Cho and Jane Chung; Editing by Joseph Radford)