South Korea has locked in 273 million barrels of crude oil and 2.1 million tons of naphtha from Middle Eastern and Central Asian suppliers through the end of this year, enough to sustain normal economic activity for over three months, a presidential aide said Wednesday. The move comes as the effective closure of the Strait of Hormuz (the narrow waterway connecting the Persian Gulf to global shipping lanes) has disrupted supplies that normally account for roughly 70 percent of South Korea's crude and naphtha imports. To ease the burden on industry, Seoul will also subsidise shipping costs for alternative supplies and inject up to 674.4 billion won (about $457 million) to offset higher naphtha import prices between April and June.