At more than 7.5 million barrels, April\'s imports were the highest since November 2011, and were also 42 percent more than the same month a year ago, data from the state-run Korea National Oil Corp. (KNOC) showed on Tuesday. Seoul imported more than 250,000 barrels per day of Iranian crude in April, compared with its term import agreement at 200,000 bpd this year. The boost in oil imports from Iran by South Korea, one of Iran\'s biggest customers, is seen as a slap in the face of the US which has demanded Iran\'s Asian crude customers to impose a ban on supplies from Iran. Government officials and industry sources declined to comment on the rise in imports, saying the issue was politically sensitive. South Korea\'s government has shied away from officially declaring a position on whether it will stop or reduce its Iranian oil imports. The United States is its main guarantor for security against North Korea, which has a nuclear weapons program. The western media said South Korea is seeking a waiver from US financial sanctions against Iran that were announced on Dec. 31 and which take effect end-June, but Washington has said exemptions will be granted only to countries that make big cuts to their crude imports. The United States and Europe are trying to squeeze the revenues Iran makes from oil exports in order to force it to relinquish its nuclear rights. Iran\'s oil exports, which were up to 2.2 million barrels per days (bpd) last year, have increased sharply this year, industry sources said this month, as core customers in Europe and Asia continue to buy despite European sanctions. China, the world\'s second biggest oil consumer and another major Asian buyer of Iranian crude, increased its oil imports from Iran by 50 percent in April compared to March after both sides resolved a pricing dispute.