SEOUL — North Korean leader Kim Jong Un is receiving treatment after undergoing a cardiovascular procedure early this month, according to a media report in South Korea. Kim’s conspicuous absence from the anniversary of the birthday of North Korea’s founding father and his grandfather Kim Il Sung on April 15 fueled widespread speculation over the North Korean leader’s health. Daily NK, a specialty website run mostly by North Korean defectors, cited unidentified sources inside the isolated state saying Kim is recovering at a villa in the Mount Kumgang resort county of Hyangsan on the east coast after getting the procedure on April 12 at a hospital there. "Excessive smoking, obesity, and fatigue were the direct causes of Kim"s urgent cardiovascular treatment," it said. However, South Korean President Moon Jae-in’s office said that Kim was conducting “normal activities” in a rural part of the country assisted by close aides and no special movements were detected. Moon spokesman Kang Min-seok said earlier there was nothing to confirm on the speculation over Kim’s health. Meanwhile, the United States is seeking details about Kim"s health after receiving information that the North Korean leader was in critical condition after undergoing cardiovascular surgery last week, a US official said. The Trump administration wasn"t sure whether Kim was dead or alive, said the official, who asked not to be identified. CNN had earlier reported, citing a US official with direct knowledge of the matter, that Kim may be in "grave danger" after the surgery. The White House declined to comment on the CNN report. The health of North Korea"s leader is one of the state"s most closely guarded secrets, typically only known by a few people in the inner circle of leadership. — Agencies